Glossary of Automotive Terms – M

Letter M – Dictionary of Automotive Terms

100% (neat) methanol
85% methanol and 15% unleaded gasoline by volume, used as a motor fuel in FFVs.
Abbreviation for mud and snow, as in M+S tire. A tire with a tread design (usually large lugs with wide spaces between them) which gives the maximum traction in mild mud and snow, but is suitable for highway speeds.
M+S tire

Mud and snow tireMud and snow tire

Abbreviation for mud and snow tire, as in M+S tire. A tire with a tread design which gives the maximum traction in mild mud and snow, but is suitable for highway speeds.

Abbreviation for motor assisted bicycle — usually an electric motor
  1. Relative ease or difficulty in forming.
  2. The malleable characteristics of metal when cutting or forming on screw machines. Same as free machining
Machine drive
The direct process end use in which thermal or electric energy is converted into mechanical energy. Motors are found in almost every process in manufacturing. Therefore, when motors are found in equipment that is wholly contained in another end use: (such as process cooling and refrigeration), the energy is classified there rather than in machine drive.
Machined surface
A smooth surface of metal such as the top of a cylinder block.
Machine patch
A new layer of asphalt is placed on sections of the road, perhaps leaving some gaps depending on condition. First a layer of liquid asphalt or tack coat is sprayed on the road. Next, fabric may be placed on any badly broken areas for added strength. Finally hot asphaltic concrete is applied, raked and rolled to a prescribed density. Work moves quickly and you can drive on the new asphalt as soon as the rolling is complete. The work must be done when the ground is dry and reasonably warm.
Machine room
Area where commercial and industrial refrigeration machinery — except evaporators — is located.
Machinery cargo
Machinery spaces
Machine screw
  1. A screw with thread running the length of the shank and available with a variety of different heads
  2. A straight shank fastener for binding metal to metal by going through a pre-tapped hole or nut. Its head may be one of four common shapes:
An operation which shapes metal parts by carving away excess material as chips produced in a sequential process of turning, milling and grinding operations.
Machinists’ caliper
A measuring tool with two curved arms for inside or outside measurement; the reading taken with the arms is transferred to a steel rule or micrometer to attain the exact value
Machinists’ hammer
A Ball pien hammer
MacPherson strut

Mac_Pherson strutClick image to supersize

A suspension piece which employs a Coil spring and shock absorber attached to the lower A-arms and the top of the front body structure. Originally it had a Lateral link with an Anti-roll bar instead of the lower A-arm. It was first invented by a Ford of England engineer, Earle S. MacPherson.

MacPherson strut tower
A sheet metal panel surrounding the upper mount of the MacPherson strut at the side panels of the engine compartment; it may be a separate panel fitted by spot-welding or a deep-drawn section of the side panel shaped to take the upper strut end. Also called suspension leg turret
MacPherson suspension
A suspension layout incorporating Macpherson struts
Any very large molecule, such as a synthetic polymer used in the manufacture of plastic
With very large molecules
Made available
A vehicle is considered Made available if it is available for delivery to dealers or users, whether or not it was actually delivered to them. To be Made available, the vehicle must be completed and available for delivery; thus, any conversion to be performed by an OEM Vehicle Converter or Aftermarket Vehicle Converter must have been completed.
Abbreviation for Mass airflow meter. A sensor used to measure the amount of intake air entering the engine on some fuel injection systems
Abbreviation for Mass Airflow Sensor Ground
Abbreviation for manifold air/fuel temperature sensor
Swiss engine makers, the initials stand for Motosacoche Acacias Geneva. The company also produced complete Motosacoche motorcycles
  1. Abbreviation for magneto.
  2. Abbreviation for magnesium wheel, or Mag wheels
Mag alloy
Magnesium alloy, a strong lightweight metal used for many components, particularly wheels
  1. A special chemical process, used to check parts for cracks.
  2. A magnetic method of determining surface and subsurface defects in metals.
Magnesium acetate
Magnesium chloride
A soluble compound in liquid form produced from magnesium carbonate and hydrogen chloride used to deice road or pre-wet salt before applying it to roads. It works like anti-freeze by lowering the freezing temperature of water, preventing ice from forming a strong bond to the road.
Magnesium wheel
An alloy wheel.


  1. A piece of magnetized steel that will attract all ferrous material. The Permanent magnet does not need electricity to function and will retain its magnetism over a period of years. Often shaped into the letter U.
  2. The part of the electric actuating mechanism, which when energized is attracted to the armature, creating a controlled force to apply the brake(s).
Magnetically controlled electronic ignition
Magnetic blowout
A device which extinguishes an electric arc. A magnetized coil moves one terminal to a cool surface or stretches out the arc.
Magnetic clutch
  1. A coupling device used to turn the compressor off and on electrically.
  2. Clutch built into automobile air conditioning compressor flywheel and is operated magnetically which allows the pulley to revolve without driving compressor when the refrigerating effect is not required.
Magnetic core
Magnetic center of a magnetic field.
Magnetic drain plug
A plug or bolt fitted in the sump or oil pan to collect metal filings
Magnetic Electric Brake
Magnetic field
  1. The area encompassed by the magnetic lines of force surrounding either a bar magnet or electromagnet. The flow of magnetic force between the opposite poles of a magnet.
  2. Invisible lines of force surrounding a magnet or a conductor with current flowing through it.
  3. The region around a magnet or an electric current-carrying wire is a volume of special properties. The most familiar is the torque experienced by a small magnet when placed in such a region.
Magnetic flux
Lines of force of a magnet.
Magnetic gasket
Door-sealing material which keeps door tightly closed with small magnets inserted in gasket.
Magnetic materials
An object made of certain pure metals (esp. iron and nickel) or an alloy of them such that when it encounters a magnetic field it is demonstrates an attraction or repulsion.
Magnetic north pole
End of magnet Out of which magnetic lines of force flow.
Magnetic permeability
  1. A test that determines the level of magnetism.
  2. A factor, characteristic of a material, that is proportional to the magnetic induction produced in a material divided by the magnetic field strength.
Magnetic pick-up
  1. A pulse generator consisting of a stator with a permanent magnet and a rotor, which induces an AC voltage in the inductive winding by the periodic change of the air gap between stator and rotor. Magnetic pick-ups attached to the distributor for ignition triggering have as many teeth on the pole piece (stator) and on the trigger wheel (rotor) as the engine has cylinders. Some magnetic pick-ups have a bowl-like rotor with ferrite rods inserted in the walls. Magnetic pick-ups on the crankshaft flywheel act as reference mark sensors.
  2. A tool with flexible or rigid shaft and magnetic tip used to retrieve dropped nuts, bolts, and other metal parts from hard-to-reach places.
Magnetic pick-up assembly
A pulse generator consisting of a stator with a permanent magnet and a rotor, which induces an AC voltage in the inductive winding by the periodic change of the air gap between stator and rotor. Magnetic pick-ups attached to the distributor for ignition triggering have as many teeth on the pole piece (stator) and on the trigger wheel (rotor) as the engine has cylinders. Some magnetic pick-ups have a bowl-like rotor with ferrite rods inserted in the walls. Magnetic pick-ups on the crankshaft flywheel act as reference mark sensors
Magnetic pick-up tool
A tool with flexible or rigid shaft and magnetic tip used to retrieve dropped nuts, bolts, and other metal parts from hard-to-reach places.

Magnetic plug
A plug or bolt fitted in the sump or oil pan to collect metal filings
Magnetic screwdriver
  1. A screwdriver with a magnetized shank.
  2. A screwdriver tool with hexagon socket end to accept and operate hex bits and hold them securely by magnetism. Some also have a hollow handle for storing the bits
Magnetic south pole
The part of a magnet into which magnetic flux lines flow.
  1. A field of force which causes a magnet to attract materials made of iron, nickel-cobalt or other ferrous material.
  2. As related to stainless fasteners, 300 series stainless is non-magnetic in its raw material condition. Cold working can sometimes induce traces of magnetism in 300 series, depending on the severity of cold working and chemical composition of the stainless. A rise in magnetism is related to an increase in tensile strength and work hardening caused by the heat and friction of cold forming and does not reduce corrosion resistance or cause any molecular change in austentic raw material. A higher portion of nickel can increase stability in stainless, thus decreasing work hardening and any possibilities of magnetism. Brass and silicon bronze are non-magnetic.
Made magnetic
  1. An electrical device which generates electrical current when it is rotated by an outside source of power. It needs no outside source of power such as a battery. It may produce either low or high tension current.
  2. A flywheel magneto ignition system
Magneto file
A tool for filing ignition points and other small objects
Magneto ignition
A compact assembly of a magneto generator, an ignition coil, and a distributor. Ignition voltage is induced within the magneto by the movement of a coil relative to the poles of a permanent magnet. Because it needs no battery, the system is particularly suited for small engines, e.g., motorcycles, outboard engines, etc.
Magnetomotive force (mmf)
The magnetic energy supplied with the establishment of flux between the poles of a magnet
Magneto puller
A tool which screws into the center of the magneto to force the magneto away from the shaft on which it rides.
Magnet sensor
Magneto supported CDI
A capacitive discharge ignition using a generating coil in the magneto to produce primary ignition current


Mag wheel

Mag wheelMag wheel

Lightweight, sporty wheels made of magnesium. The term mag is often applied to aluminum and aluminum and steel combination wheels. In some applications (e.g., wheelchair wheels) one-piece plastic wheels are called mag wheels to distinguish them from wire-spoke wheels.

British term for household AC voltage.

Main bar
The bar on a convertible top which carries the main load when the top is raised and taut, and defines the hinge point for the folding motion. Also called main bow
Main beam
British term for High beam
Main beam indicator
British term for High beam indicator
Main bearings
The bearings in the engine block that support the crankshaft.
Main bearings
Main bearing support
A steel plate that is installed over the main bearing caps to increase their strength for racing purposes.
Main bearing supports
Main bow
The bar on a convertible top which carries the main load when the top is raised and taut, and defines the hinge point for the folding motion. Also called main bar
Main burner
A device or group of devices essentially forming an integral unit for the final conveyance of fuel or a mixture of fuel and air to the combustion zone, and on which combustion takes place to accomplish the function for which the equipment is designed.

Main combustion chamber
With diesel engines, the fuel may be injected in three different locations in the prechamber, the swirl chamber, or the main combustion chamber (for direct injection engines), depending on the process used
Main deck
  1. The continuous deck of a ship running from fore to aft. The freeboard is measured from this deck.
  2. Usually the deck immediately below the shelter or weather deck.
Main fuel circuit
Carburetor circuit that controls air-fuel ratio from three-fourths to full throttle opening.
Main jet
  1. The primary, large fuel orifice in a carburetor through which most of the fuel flows.
  2. A carburetor fuel metering jet, usually mounted at the base of the carburetor body. Controls air-fuel ratio from three-fourths to full throttle.
The most heavily used tracks of a railroad.
Mainline pressure
Main member
The primary chassis rail
Main metering circuit
The cruising circuit or the high speed circuit. It supplies the correct air/fuel mixture to the engine during cruising and high-speed conditions. Also called Main metering system
Main mixing well
Main well main nozzle Main delivery tube
Main mixture discharge nozzle
The jet through which the gasoline and air is fed into the carburetor barrel where it becomes the air/fuel mixture
Main petal
The primary petal of a dual-stage reed valve. The opposite is Subsidiary petal. In dual-stage reed valves, the subsidiary petal opens first
Main pressure
Main regulating system
The carburetor components are divided into the fuel intake control, the main regulating system, the idle system, and the staring aids. The main regulating system includes the main jet, jet needle, needle jet, and throttle valve, whose purpose it is to provide an appropriate amount of fuel and air to the carburetor
The caps which secure the crankshaft.

Main Seal Bearing
Main shaft
The transmission Output shaft
Main sun visor
In dual visor systems, the main visor is moved sideways and the secondary visor is flipped down, thus shielding the driver from the sun from both the front and side
The work undertaken by a car owner to keep his vehicle in good working order; typically checking the tires, lights, oil and coolant levels, windscreen wipers, and seat belts. Compare Service
Something that requiring no work in order to be kept operational
Maintenance-free battery
A battery with a permanently sealed top, thus requiring no topping-up of water or electrolyte.
Maintenance manual
A book of instructions detailing routine maintenance
Maintenance Reporting Standards
Main triangle
Main Valve Shutoff
Main venturi
Large venturi cast into the carburetor main body
Main well
The reservoir in which fuel for the main system is stored. The main well is located in the main body casting. It is connected to the venturi area by the discharge nozzle
Main-well tube
A perforated tube which extends from an air bleed in the top of the air horn down into the main well. Admits air from the air bleed into the main well to emulsify the fuel in the main well. Improves idle response and stability when the engine is hot and prevents fuel percolation and general hot-starting problems. Also improves response in the main metering circuit during part throttle conditions. Also called Emulsion tube
See Force Majeure.
Major diameter
  1. On a bolt or screw, the diameter measured from the crest of a thread to the corresponding crest on the opposite side of the bolt or screw
  2. Largest or outside diameter of the screw threads.
  3. On a straight thread, the diameter of the coaxial cylinder which would pass through the crests of an external thread or the roots of an internal thread.
Brand name of a car or truck (i.e., Chevrolet, Ford, Dodge, Honda).
Make-and-break Switch
Male end
A plug, pin, or protrusion which fits into a receptacle (female end).
Make the trip?
Trucker slang for cb signal reception as in ‘Did my signal make the trip?’
Male thread
Something with external threads like a bolt or screw. Female threads are found in nuts.
Problem in system that affects normal operation
Malfunction indicator light
(MIL) an electric circuit between the computer and the check engine or service engine soon light on the instrument panel of a computer equipped vehicle
Chevrolet Malibu BooksClick image for books on
Chevrolet Malibu

A model of car produced by the Chevrolet division of General Motors from 1964 to current.

Malibu Hybrid
A Chevrolet midsize Hybrid sedan similar to the Saturn Aura Green Line that uses a Belt Alternator Starter hybrid system.
Malleable castings
  1. Cast forms of metal which have been heat-treated to reduce their brittleness.
  2. A casting which has been toughened by annealing
Short form for manual transmission See: Dead Man
Management Control System
Management District
Management system
Man door
In a garage, there is a large door through which a vehicle can enter; but the smaller door (usually about 3’x7′) is the door through which a person enters and it is the man door.
A round shaft used to mount a stone, cutter, saw, etc.
To drive or steer a vehicle around obstacles, change direction, or moving in a confined space.
The ease with which a vehicle can be steered around objects
A non-magnetic metal which improves strength and hardness to steel and bronze

Manganese bronze
An alloy of copper, zinc, and manganese
Manganese phosphate coating
A phosphate coating with added manganese to increase resistance to wear and fatigue
Manganese Tricarbonyl


  1. A hole or opening in a street, with a removable cover, through which an underground structure, such as a sewer or conduit, can be entered for repair or inspection.
  2. A hole cut in a bulkhead, tank top, etc., to allow the passage of a man.
  1. A control document used to list the contents (individual shipments) during loading and from which the contents are checked during unloading.
  2. A document that lists all of the products being transported; used when loads are combined. The Manifests (Loading and Driver) are generated by transportation in Phoenix. A loading Manifest will be printed to the Warehouse so that they know who will be picking up the load and how to properly load the trailer. A Driver Manifest will be auto-faxed to the carrier so that they know the order of the stop(s), the address and shipping requirements of the client(s).
  3. A report that tells the crew how many passengers are riding (passenger trains) or what is being shipped as the contents of a car (freight trains).

See Load Manifest.

  1. A pipe or number of pipes connecting a series of holes or outlets to a common opening.
  2. A device which controls refrigerant flow for system test purposes by means of hand valves which can open or close various passageways connected together inside the manifold. Used in conjunction with manifold gauges and service hoses
  3. The conduit of an Appliance that supplies gas to the individual burner.
Manifold absolute pressure
(MAP) manifold pressure measured on the absolute pressure scale, an indication of engine load. At sea level, MAP = 1 bar (14.5 psi)
Manifold absolute pressure sensor

  1. A detection device which monitors the engine’s intake manifold pressure and transmits the data to the engine controller. A pressure-sensitive disk capacitor used to measure air pressure inside the intake manifold. The Map sensor sends a signal to the computer which uses this information to determine load conditions so it can adjust spark timing and fuel mixture. Also called Manifold pressure sensor or Pressure differential sensor
  2. A detection device that measures absolute air pressure in the intake manifold.
Manifold air temperature sensor
(MAT sensor) sensor that monitors the temperature of the air entering the intake manifold
Manifold charge temperature sensor
(MCT) same as the air charge temperature sensor (ACT)
Manifold control valve
(MCV) a thermostatically operated valve in the exhaust manifold for varying heat to the intake manifold with respect to the engine temp. Also called exhaust heat control valve
Manifold gauge set
A complete, testing assembly consisting of a high side gauge, a low side gauge and a high side gauge, a test manifold, and a set of service or charging hoses. Also, can be used to discharge refrigerant, evacuate air and moisture, and charge air conditioning system with refrigerant
Manifold heat control valve
A valve placed in the exhaust manifold, or in the exhaust pipe, that deflects a certain amount of hot gas around the base of the carburetor to aid in warmup.
Manifold heater
A system used to improve the cold start behavior of an engine, consisting of heating ducts incorporated into the intake manifold that are connected to the water cooling system of the engine; alternatively, an electric heater may be used.

Manifold injection
Oil injection system that pumps oil into the intake port of a two-stroke engine.
Manifold pressure controlled
(MPC) a fuel injection system which determines engine load based on intake man pressure
Manifold pressure sensor
A sensor that reads pressure changes in the intake manifold in relation to barometric pressure. Also known as Manifold vacuum sensor, Manifold absolute pressure sensor, Pressure differential sensor, or Vacuum sensor
Manifold runners
Single passage in a manifold from one cylinder to the major manifold opening
Manifold, service
Chamber equipped with gauges and manual valves, used by service technicians to service refrigerating systems.
Manifold surface temperature sensor
A sensor that provides information on the surface temperature of the intake manifold
Manifold vacuum
As the pistons move down on the Intake stroke, they create a suction or vacuum in the intake manifold. This vacuum reading can be used to determine how well the engine is running.
Manifold vacuum sensor
(MVS) A sensor that reads pressure changes in the intake manifold in relation to barometric pressure. Also known as Manifold pressure sensor, Pressure differential sensor, or Vacuum sensor
Manifold vacuum zone switch
A type of manifold vacuum sensor (MVS) that dramatically changes the sensor output signal level upon reaching a preselected level or zone of manifold vacuum.
British spelling of Maneuverability
British spelling of Maneuver
  1. A device for measuring a vacuum, consisting of a U shaped tube partially filled with fluid. One end of tube is open to air, the other is connected to a chamber in which vacuum is to be measured. A column of mercury 30 in. high equals 14.7 psi, which is atmospheric pressure at sea level. Readings are given in inches of mercury (Hg)
  2. Instrument for measuring pressure of gases and vapors. Gas pressure is balanced against column of liquid, such as mercury, in U-shaped tube.
  1. Originally something done by hand, but later has come to mean something that is done without power assistance. For instance, manual brakes on a car are operated by the driver’s foot, not hand; but if the brakes are power assisted, they are no longer manual brakes.
  2. A colloquial term for a vehicle with manual transmission.
  3. A book of instruction.
Manual adjuster
A type of brake adjuster that must be adjusted from time-to-time, with the use of a hand tool
Manual bleeding
A technique for bleeding hydraulic brakes that requires two people. One pumps the brakes, and the other opens and closes the bleeder screw.
Manual choke
A linkage system which begins with a knob on the dash which can be pulled to activate and pushed to de-activate. The knob is attached to a cable and the other end of the cable is attached to a the Butterfly valve on the carburetor. Because many drivers had difficulty knowing when to use the choke knob, manufacturers developed the Automatic choke system which decides this information for the driver.
Manual-crank window
Manual frost control
Manual control used to change operation of refrigerating system to produce defrosting conditions.
Manual gearbox
Manual hydraulic brake system
A hydraulic-type brake system that uses unassisted driver effort.
Manual Main valve shutoff
A manually operated valve in the fuel line for the purpose of completely turning on or shutting off the fuel supply to fuel utilization equipment, except to a pilot provided with independent shutoff valves.
Manually operated window
A window (usually a side windo) operated by turning a lever by hand. Compare Electric window
Manual panel cutter
Cutting tool drawn manually across a panel surface to cut to the desired shape
Manual steering
A Steering system that does not have a Power booster to reduce the effort of steering changes especially during slow movements such as parallel parking.
Manual transmission

Manual transmissionClick image to supersize

(MT or M/T) A transmission system in which gears are selected by the driver by means of a hand-operated Gearshift and a foot-operated clutch. In a motorcycle the clutch is hand-operated and the gearshift is foot-operated. Contrasts with an automatic transmission. Also called a standard transmission. British term is manual gearbox.

Manual valve
(MV) A control in an automatic transmission which distributes Line pressure to the various control valves and pistons which operate the multi-plate or band brakes or the clutches; operated by the driver via the selector lever
Manual valve shutoff
A manually operated valve in a fuel line for the purpose of completely turning on or shutting off the fuel supply to fuel utilization equipment.
Manual version
A passenger car with a manual transmission
Manufactured gas
A gas obtained by destructive distillation of coal or by the thermal decomposition of oil, or by the reaction of steam passing through a bed of heated coal or coke. Examples are coal gases, coke oven gases, producer gas, blast furnace gas, blue: (water) gas, carbureted water gas. Btu content varies widely.
Manufacturers And Traders
Manufacturers Association
Manufacturer discounts
In some leases, particularly subvented leases, the manufacturer reduces the MSRP which lowers the purchase price of the vehicle, which the lease is based on. This is a form of capitalized cost reduction.
Manufacturer’s manual
A service manual published by a vehicle’s manufacturer. It is usually specific to one model.
Manufacturer’s performance ratings
The performance data as specified by the car manufacturer
Manufacturer’s suggested retail price
(MSRP) The suggested retail price the dealer is asking. Generally the same as the sticker price. Dealers typically sell at a discount to this price.
Manufacturer Vehicle
  1. Process technology (i.e., metal forming, machining, injection molding, blow molding, die casting, forgings, electronics/electrical, assembly, coating/plating); capacity utilization (in percent); production volumes; strategic alliances (e.g., joint ventures, technology agreements).
  2. An energy-consuming subsector of the industrial sector that consists of all facilities and equipment engaged in the mechanical, physical, chemical, or electronic transformation of materials, substances, or components into new products. Assembly of component parts of products is included, except for that which is included in construction.
Manufacturing division
One of ten fields of economic activity defined by the Standard Industrial Classification Manual. The manufacturing division includes all establishments engaged in the mechanical or chemical transformation of materials or substances into new products. The other divisions of the U.S. economy are agriculture, forestry, fishing, hunting, and trapping; mining; construction; transportation, communications, electric, gas, and sanitary services; wholesale trade; retail trade; finance, insurance, and real estate; personal, business, professional, repair, recreation, and other services; and public administration. The establishments in the manufacturing division constitute the universe for the MECS: (an EIA survey).
Manufacturing establishment
An economic unit at a single physical location where mechanical or chemical transformation of materials or substances into new products are performed.
Manufacturing Resource Planning
(MRP II) System of manufacturing controls using computers. Affects purchasing, materials management, inventory control, and production management.
Lift trucks that raise the operator as well as the load. Two types of man-up lift trucks are turret trucks and order selectors.
  1. Abbreviation for Manifold absolute pressure
  2. Abbreviation for manifold air pressure sensor
A pictorial representation of a series of data points stored in the memory of the control unit of system with complete engine management. The control unit refers to the map to control variables such as fuel injection pulse width and ignition timing

Map-controlled ignition
A microprocessor-controlled ignition system with electronic ignition timing by means of an ignition map stored in the control unit memory. The engine speed is sensed by Hall generators at the distributor or magnetic pick-ups on the crankshaft, the load signal being given by pressure sensors which measure the air mass or air per unit of time
Map light
An interior light to facilitate, for example, map reading.

A stabilized methyl acetylene-propadiene fuel gas. It is a Dow Chemical Co. product.
Mapped ignition
A microprocessor-controlled ignition system with electronic ignition timing by means of an ignition map stored in the control unit memory. The engine speed is sensed by Hall generators at the distributor or magnetic pick-ups on the crankshaft, the load signal being given by pressure sensors which measure the air mass or air per unit of time
MAP sensor
Abbreviation for Manifold absolute pressure system sensor which tells the computer how much pressure is in the intake manifold
Mexican assembly plant located near the U.S.-Mexican border where most production is exported to the United States.
Mexican assembly plant located near the U.S.-Mexican border where most production is exported to the United States.
A special decorative painting effect with rotating brushes
The return an intermediary achieves on the selling price of the article. That is, if the intermediary buys a product for $1 and sells it for $1.50, the margin is calculated. For example, .50 (i.e., $1.50 – $1) divided by $1.50, or 33%.

Margin bracket
A bracket connecting a side frame to the margin plate at the bilge
Margin line
A line, not less than 3 inches below the top of the bulkhead deck at side, defining the highest permissible waterplane in the final condition of sinkage, trim and heel
Margin Plate
The outboard row of plates of the inner bottom, connecting to the shell plating to the bilge.
Marine Diesel Oil
(MDO) Marine Diesel oil is a middle distillate fuel oil which can contain traces often percent: (10%) or more residual fuel oil from transportation contamination and/or heavy fuel oil blending. The MDO does not require heated storage.
Marine freight
Freight transported over rivers, canals, the Great Lakes, and domestic ocean waterways.
Letters, numbers or other identification marks placed on a package for identification purposes. Also called Markings.

Marker lamp
A light which is mounted on the extreme edges of the roof of a truck to show the maximum height and width of a vehicle. Also called clearance lamp.

Marker light
A Side marker light
Market share
The percentage of total sales represented by an individual manufacturer/importer, make or nameplate.
Market Vehicles
Letters, numbers or other identification marks placed on a package for identification purposes. Also called Marks.

Mark sensor
The return an intermediary achieves on the cost price of an article. Using the same example described above, mark-up is .50 divided by $1, or 50%.
Marles steering
A form of cam-and-roller steering
A pointed tapering tool which is used in separating strands of rope or cable in splicing.
A vehicle brand of which the following models are classic cars:

  • all 16-cyl. models
  • 1925 model 74
  • 1926 model 74
  • 1927 model 75
  • 1928 model E75
  • 1930 model Big 8
  • 1931 model 88 and Big 8
A particular brand name of a vehicle. Also spelled marquee
A particular brand name of a vehicle. Also spelled marque
(‘Marshaller’ derived from ground-crew who marshal aircraft on airport aprons.) In the context of off-road operations, taken to mean the detailed direction of a vehicle by a marshaller outside the vehicle who is able to see all four wheels and also the difficult ground being traversed. Marshalling should be undertaken when there is the danger of damaging tire sidewalls or the underside of the vehicle on rocks or other obstacles.
Named for Robert Martens, a German metallurgist, martensitic grades of stainless steel (types 410, 416, and 420) have a high carbon content which reduces corrosion resistance, but allows a sharp increase in tensile strength after heat treatment. Because of its high tensile strength, martensitic stainless is used for highly stressed parts such as control rod mechanisms, valves, shafts, pump parts under high stress. Martensitic stainless is magnetic, contains no nickel, loses toughness in very cold temperatures, and may have tendency to become brittle. Used in approximately 5% of stainless fasteners. Its corrosion resistance is not as good as austentic or ferritic stainless, so martensitic fasteners are used in mild atmospheres.
Abbreviation for mixture adjust screw


MaseratiClick image for books on

A vehicle brand of which the 1925-1948 models with required application are classic cars. The 1957-64 3500/3700 GT models are milestone cars.

A cyclist who habitually pedals hard in a high gear, at a slow cadence. The opposite of a spinner.
To cover the surrounding area when paint spraying to protect it from splashes
The preparation before painting where those items not to be painted are covered over.

Masking tape
An adhesive tape used to cover surfaces that border an area to be painted, so as to protect them
The quantity of matter a body contains. Mass is measured in kilograms (and often incorrectly called weight). The mass of a body does not change if, for example, it is moved to the Moon where the force of gravity is less.

Mass airflow meter
(MAF) device for measuring the mass flow of air into an engine.

Mass damper
A device which reduces or prevents vibrations or oscillations, usually a weight which counteracts (balances) undesirable motions; used on drive shafts of some FWD cars
Mass Flow
Mass Meter
Mass-produced car
A car which is manufactured in great numbers to a standard pattern and with extensive mechanization
Mass Sensor
Mass tone
The tone of a paint as it appears from the color of the paint in the can; this is required for formulating the ingredients of a paint tone.


Mass transit system
A system designed to transport large numbers of people or goods
A tall vertical or raked structure, usually of circular section, located on the centerline of a ship and used to carry navigation lights, radio antennas and cargo booms
The primary or controlling device. A secondary or dependent device is called a slave.

Master brake cylinder
Master Carton
A large box that is used to hold and protect smaller cartons or packages of product. Using a master carton reduces handling as one larger piece instead of multiple small pieces.
Master con rod
In a two-stroke dual piston engines, the connecting rod that is articulated directly on the crankshaft.

Master cylinder
  1. The primary component for pressurizing fluid in a hydraulic system. Used in the braking system, it supports a reservoir for holding brake fluid and is activated each time the driver depresses the brake pedal.
  2. The device that converts mechanical pressure from the brake pedal into hydraulic pressure that is routed to the wheels to operate the friction assemblies.
Master cylinder pushrod
The rod that transmits the movement and force of the driver from the brake pedal lever to the master cylinder piston.
Master Gauge
A thread-plug gauge which represents the physical dimensions of the nominal or basic size of the part. It clearly establishes the minimum size of the threaded hole and the maximum size of the screw at the point at which interference between mating parts begin.
Master link
Master link
A special link on a chain that can be opened by flexing a plate, removing a screw, or some other means besides driving out a rivet. This allows a convenient way of separating the chain. The retaining spring clip is shaped like a fish with a round head and twin tails. This illustration helps to determine the position of the clip because the fish moves in the direction of chain movement. When installed in reverse, the clip may come off. Also called joining link or connecting link.
Master model
The first precision model of an automobile based on a clay model or CAD-data; essential for the manufacture of prototypes
Master Pack
A carton containing a specific number of products or multiple case quantities.
Master pattern
The first precision model of an automobile based on a clay model or CAD-data; essential for the manufacture of prototypes
Master switch
Master vac
Master vac servo unit
Masthead light
A white light situated on the fore and aft centerline of a ship
Any heavy-bodied adhesive of such a consistency that it must be applied by notched trowel, gob, or by buttering methods
The reduction of rubber to a pulp preparatory to making tires
Mastic seam sealant
Soft waterproof sealant for joints
  1. A dull, not shiny, paint finish. Also spelled matt.
  2. A covering.
  3. Abbreviation for Manifold Air Temperature
MatadorClick image for books on

An automobile manufactured by AMC

Matching & Tagging
Two or more strands are to vary with a given tolerance. Chains are to be measured under a specified measuring load.
Matching numbers
A set of numbers on a car which specify and can be used to verify the originality of the components of a car ranging from color to the engine.
To fit together
Material Handling
The services and processes the warehouse must use to move store and otherwise handle materials.
Material safety data sheets
(MSDS) Sheets provided by the manufacturer that contain information on the handling of hazardous wastes, the use of protective equipment and the procedures to follow in case of an accident
Mathematical model
A computer model, based on an X-Y-Z coordinate system, of a surface or surfaces. An electronic machine that can take and record precise measurements of three-dimensional surfaces. Typically, a scanner has an articulated arm with a probe at the end that either physically touches the surface or ‘scans’ it with a laser probe. The scanner, by assigning digitized numbers based on an X-Y-Z coordinate system and a zero point, forms a point-by-point mathematical model of the surface. (Also called point taker and coordinate measuring machine.) Also called Math model.
Math model
See Mathematical Model
Fitting together; matching
Mating gears
Gears which mesh together
Mating parts
Two or more parts that contact each other during operation and setup wear patterns
Mating surface
A surface which interacts perfectly with another
Mating thread
A thread which engages with a corresponding thread, such as the male and female threads of a nut and bolt
MAT sensor
Abbreviation for Manifold air temperature sensor. The same as IAT. The MAT circuit is identical to the CTS circuit.
That portion of the mold which surrounds the tire transferring heat to the uncured rubber and forming the tread pattern.
A dull, not shiny, paint finish. Also spelled mat
MaximaClick image for books on

A model of automobile manufactured by Nissan in Japan

Maximum Allowable Load
A maximum tension a chain may be safely subjected to. This value should never be exceeded by actual design load factored by speed, temperature and dynamic adjustments as applicable.
Maximum brake power
The maximum power of an engine as measured by a dynamometer
Maximum diameter brake drum
The largest diameter to which a brake drum can be machined or worn before it becomes unsafe. This dimension is usually stamped or cast into the drum near the hub. Typically, this is 0.060′ over original diameter.
Maximum ignition Time
The maximum allowable time for the specified function of any device.
Maximum Material Limit
The maximum limit of size of an external dimension or the minimum limit of size of an internal dimension.
Maximum operating pressure
(MOP) The steady-state or transient gauge pressure at which a part or system operates. It shall not exceed the allowable working pressure, and it is usually kept at a suitable level below the setting of pressure-limiting/relieving devices to prevent their frequent functioning.
Maximum power
The maximum power of an engine as measured by a dynamometer
Maximum power point tracker
(MPPT) An electronic circuit which assures the delivery of peak power from a solar cell to its load. A solar cell normally delivers peak power when operated at about the knee of its characteristic current-voltage curve.
Maximum regulation capacity
The high limit of flow below which is found acceptable regulating characteristics.
Maximum trailer weight
Also known as towing capacity; the heaviest trailer the vehicle is rated to tow. Towing capacity is typically based on the vehicle plus a driver of 150 pounds. The weight of additional passengers and/or cargo should be deducted from the maximum trailer weight.
A centimeter-gram-second electromagnetic unit which produces an electromagnetic force of 1 abvolt in a circuit of one turn linking the flux, as the flux is reduced to zero in 1 second at a uniform rate. (1 abvolt = 10-8 volt in the absolute meter-kilogram-second system). Abbreviated aV.
A vehicle brand of which the 1925-1948 models are classic cars.
MazdaClick image for books on

A model of automobile manufactured in Japan by the Mazda Motor Corporation. It includes 323 (1980-94), 626 (1983-2002), 929 (1981-95), B2200 (19__-93), B2300 (1994-2007), B2500 (1998-2001), B2600 (19__-93), B3000 (1994-2007), B4000 (1994-2007), CX-7 (2007), CX-9 (2007), MAZDA3 (2004-08), MAZDA5 (2006-07), MAZDA6 (2003-08), Mazdaspeed3 (2007), MAZDASPEED6 (2006-07), Miata MX-5 (1990-2008), Millenia (1995-2002), MPV (1989-2006), MX-3 (1992-95), MX-6 (1988-97), Navajo (1991-94), Protege (1990-2003), Protege5 (2002-03), RX-7 (1993-95), RX-8 (2004-07), and Tribute (2001-06)

Mazda RX
Mazda RXClick image for books on
Mazda RX
Abbreviation for Minor Betterment
Thousands of British Thermal Units (82 MBH = 82,000 Btu).
Abbreviation for Mixture Control
A vehicle brand of which the TV6 and 8 models built during the ‘classic era’ of 1925-1948 models are classic cars.
Abbreviation for Molten carbonate fuel cell
McPherson strut
Abbreviation for Maximum continuous rating
Abbreviation for Mixture Control Solenoid: (GM)
M/C solenoid
Abbreviation for Mixture control solenoid
Abbreviation for mixture control solenoid valve
Abbreviation for Manifold charge temperature sensor
Abbreviation for Microprocessor control unit
  1. Abbreviation for Manifold control valve
  2. Abbreviation for mixture control valve
Abbreviation for Marine Diesel Oil–A middle distillate fuel oil which can contain traces often percent: (10%) or more residual fuel oil from transportation contamination and/or heavy fuel oil blending. The MDO does not require heated storage.
Abbreviation for Manifold Differential Pressure
MDXClick logo for books on
Abbreviation for Membrane Electrode Assembly
Mean distance to the sun
240 million miles; used to specify the headroom in convertibles
Mean effective pressure

  1. The average pressure of the burning fuel on the Power stroke subtracted by the average pressure on the other three strokes. Pressure is in pounds per square inch.
  2. Average pressure on a surface when a changing pressure condition exists.
Mean indicated pressure
A mathematical value that indicates the relation between the effective area of the work diagram of the two-stroke engine and the movement of the piston
Mean time to repair
(MTR) The time interval (hours) that may be expected to return failed equipment to proper operation.
Measuring Load
The specified standard load under which a chain is to be measured for length. (1% of tensile strength).
Measuring method
Measuring technique
Measuring tool
A person who works on engines or machines.

Mechanical advance
Mechanical advantage
The ratio of the force exerted to the force applied. A manual brake pedal may have a mechanical advantage, or pedal ratio of 5 to 1.
Mechanical bond
The joining of two or more materials by holding them together with bolts or clamps
Mechanical brake
A brake system which uses levers and cables or rods to apply the brakes rather than hydraulics.

Mechanical brakes
Service brakes that are actuated by a mechanical linkage such as rods or cables (rather than hydraulic lines) connecting the brakes to the brake pedal. The Parking brake on most vehicles is mechanical.
Mechanical caliper
A disc brake caliper actuated by a lever and cam rather than hydraulic fluid.
Mechanical cycle
Cycle which is a repetitive series of mechanical events.
Mechanical degree
The popular physical understanding of degrees (360°=1 rotation)
Mechanical efficiency
An engine’s rating as to how much of the potentialhorsepower is wasted through friction within the moving parts of the engine. The ratio between the Indicated horsepower and the Brake horsepower of an engine.
Mechanical face seal
A shaft seal consisting of two highly polished mating surfaces, one surface being connected to the shaft (rotating element) and the other to the casing (stationary element)
Mechanical fade
Brake fade caused by heat expansion of the brake drum away from the brake linings. Not a problem with disc brakes.
Mechanical galvanizing
Mechanical-hydraulic booster
A power booster that uses hydraulic pressure from the power steering pump to increase brake application force.
Mechanical ignition timing
Centrifugal and vacuum advance
Mechanical Interrupter
A device which provides for mechanical closure of the fuel flow to the main burner by positive means such as an applied manual force through a linkage, lever handle, spring or similar mechanical means.
Mechanical plating
A deposition of zinc on another material by a cold-peening process, such as tumbling
Mechanical Properties
Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength and fatigue limit.
Mechanical protection
Where clogging materials are present in severe proportions, the air gap of Open enclosure electric motors may become clogged. Therefore, the recommendation is a Totally enclosed motor housing to obtain mechanical protection from the elements.
Mechanical seal
A shaft seal consisting of two highly polished mating surfaces, one surface being connected to the shaft (rotating element) and the other to the casing (stationary element)
Mechanical stress
A force acting across a unit area in solid materials in resisting the separation, compacting, or sliding that tends to be induced by external forces
Mechanical surface treatment
A production of a dull or rough surface or a decorative finish by grinding, brushing, polishing, or abrasive blasting
Mechanical voltage regulator
A voltage regulator using an electromagnet to open or close contact points, varying the output of a dc generator or electromagnet alternator
Mechanic installed market
(MIL) Vehicle maintenance and repair conducted by a mechanic/professional at a service outlet.
Mechanic’s creeper


Mechanic’s elbow
A shallow dent in body panels, usually on the top of a fender near the engine compartment; caused when leaning over into the engine compartment and supporting the body with elbows on the fender
Mechanics lien
When you take your vehicle to a shop to be repaired and you fail to pay your repair bill, the repair shop has a Lien on your vehicle and can confiscate and sell your vehicle to pay for the work on your vehicle.
Mechanic’s stethoscope


Abbreviation for Mobile Electronics Certification Program.
  1. Abbreviation for Mazda Electronic Control System
  2. Abbreviation for Manufacturing Energy Consumption Survey
The area that divides traffic moving in opposite directions on a single roadway. Also called Central reservation.

Median island
Median space
A gap provided in the center of a dual divided highway to allow vehicles to cross through or turn onto another road
Medium carbon steel
A type of carbon steel used extensively for sheet metal screws and grade 2 hex head bright cap screws.
Medium-duty truck
Vehicle weighing from 10,001 to 25,000 lbs.
Medium pressure
For valves and fittings, implies that they are suitable for working pressures between 125 to 175 pounds per square inch.
Medium-temperature collector
A collector designed to operate in the temperature range of 60°C to 82°C, but that can also operate at a temperature as low as 43°C. The collector typically consists of a metal frame, metal absorption panels with integral flow channels (attached tubing for liquid collectors or integral ducting for air collectors), and glazing and insulation on the sides and back.
(MJ) An SI measurement of energy (= l000 joules)
A portable instrument used to measure insulation resistance. It consists of a hand-driven DC generator and a direct reading ohmmeter.
A unit of measure for electrical resistance. One megohm is equal to a million ohms.
Instrument for measuring extremely high resistances (in the millions of ohms ranges).
Meissner effect
The expulsion of magnetic flux from the interior of a piece of superconducting material as the material undergoes transition to the superconducting phase.
Melting Equivalent
Melting point
Temperature at atmospheric pressure at which a substance will melt.
Abbreviation for Motor and Equipment Manufacturers Association.
A general term that refers mainly to the side rails and crossmembers but also to any structural hollow-section part on a vehicle.

Member of the gear train
Sun gear, internal gear, and planet carrier are the members of a planetary gear train
The separating layer in a fuel cell that acts as electrolyte (a ion-exchanger) as well as a barrier film separating the gases in the anode and cathode compartments of the fuel cell.

Membrane electrode assembly
(MEA). Structure consisting of a proton-exchange membrane with surfaces coated with catalyst/carbon/binder layers and sandwiched by two microporous conductive layers (which function as the gas diffusion layers and current collectors).
Membrane Fuel Cell
Abbreviation for Memory Calibration
Memory button
A button which operates the position of electric seats, mirrors, etc. and which stores the requirements of a particular driver in its memory
Abbreviation for Mean effective pressure.
Abbreviation for Mobile Electronics Retailers Association.
An organic chemical compound that has a sulfur like odor that is added to natural gas before distribution to the consumer, to give it a distinct, unpleasant odor (smells like rotten eggs). This serves as a safety device by allowing it to be detected in the atmosphere, in cases where leaks occur.
MercedesClick image for books on

A vehicle brand of which all 1925-1948 models with required application are classic cars.

Mercedes-BenzClick image for books on

A German vehicle brand which began in 1871, of which all 230 and up, and K, S, SS, SSK, SSKL, Grosser and Mannheim models with required application are classic cars. The following cars are milestone cars:

  • 1955-61 190 SL model
  • 1951-54 220A Coupe and Convertible
  • 1956-65 220S/220SE Coupe and Convertible
  • 1963-67 230SL Coupe and Convertible
  • 1965-67 250SE Coupe and Convertible
  • 1965-67 250 SL models
  • 1969-70 280 SL models
  • 1965-67 300 SE Coupe and Convertible
  • 1952-64 300 S, SL, SE, 300 Coupe and Convertible
  • 1964 600 model
  • 1965-70 SWB-LWB 600 models

Other models include the following: 190D (1958-89), 190E (1982-93), 260E (19__-89), 300CE (19__-93), 300D (1990-93), 300E (19__-93), 300SD (1992-93), 300SE (19__-93), 300SEL (19__-91), 300SL (1990-93), 300TE (19__-93), 350SD (1990-91), 350SDL (1990-91), 400E (1992-93), 400SE (1992), 400SEL (1993), 420SEL (19__-91), 500E (1992-93), 500SEC (1993), 500SEL (1992-93), 500SL (1990-93), 560SEC (19__-91), 560SEL (19__-91), 560SL (19__-89), 600SEC (1993), 600SEL (1992-93), 600SL (1993), C-Class (1994-08), CL-Class (1998-2007), CLK-Class (1998-2008), CLS-Class (2006-07), E-Class (1994-2008), G-Class (2002-06), GL-Class (2007), ML-Class (1998-2007), R-Class (2006-07), S-Class (1994-2008), SL-Class (1994-2007), and SLK-Class (1998-2008)

A vehicle brand of which the 1925-1948 models are classic cars.
Forest products suitable for marketing under local economic conditions. With respect to a single tree, it means the parts of the bole or stem suitable for sale.
Mercoid bulb
Electrical circuit switch which uses a small quantity of mercury in a sealed glass tube to make or break electrical contact with terminals within the tube.
The southern zone common market of Argentina, Brazil, Paraguay, and Uruguay. Mercosur enacted a common external tariff on January 1, 1995 for almost 85 percent of tariff items of the four countries; most trade among members will be duty-free.
MercuryClick image for books on
Ford’s Mercury
  1. A vehicle brand of the Ford Motor Company which began in 1939 and of which the 1967-68 Cougar XR-7 models are milestone cars. The 1946 Sportsman is a milestone car. The 1954-55 Sun Valley models are milestone cars. It includes the following:
    • Capri (1991-94)
    • Cougar (1967-2002)
    • Grand Marquis (1979-current)
    • Marauder (2003-04)
    • Mariner (2005-08)
    • Milan (2006-07)
    • Montego (2005-07)
    • Monterey (2004-07)
    • Mountaineer (1997-2008)
    • Mystique (1995-2000)
    • Sable (1986-2005, 2008-current)
    • Topaz (1984-94)
    • Tracer (1988-99)
    • Villager (1993-2002)
  2. A model of car produced by the Chevrolet division of General Motors in 1933.
Mercury barometer
A device used to determine atmospheric pressure by observing the height of a column of mercury
Mercury column
A reference term used in connection with a manometer
Mercury switch
Safety switch to prevent erroneous deployment of the air bag. Due to ecological problems associated with mercury in automobile waste, mercury switches are being replaced by suspended-mass switches, e.g., a Hamlin switch
Mercury vapor lamp
A high-intensity discharge lamp that uses mercury as the primary light-producing element. Includes clear, phosphor coated, and self-ballasted lamps.
The action of a vehicle which enters the highway from an on ramp at approximately the same speed as the highway traffic and moves between the other vehicles to become part of the highway traffic
MerkurClick image for books on

A model of automobile manufactured by Ford of Europe which included Scorpio (1988-89) and XR4Ti (1985-89)

To engage, especially gears. The opposite is Disengage.

Mesh gearbox
Meshing drive
A device for engaging the starter pinion with the flywheel ring gear
Meshing spring
A component of a pre-engaged starter which ensures that the shift lever will move to its final position and that the starter current will be switched on in case of tooth abutment
Message center
Usually a multifunctional display of a diagnostic system. A typical messages are NORMAL, DOOR AJAR, TAILGATE OPEN, LAMP OUT, WASHER FLUID LOW, etc.
Message sign
Term applied to the heat release from a human at rest. It equals 1 8.4 Btu/sq. ft./hr. (50 kcal/m2/hr or 58 W/m2).
The intersection point of a vertical line drawn through the line of buoyancy of a slightly listed vessel which intersects the centerline plane
Metacentric height
The distance from the metacenter to the center of gravity of a ship. If the center of gravity is below the metacenter the vessel is stable
Metal-arc welding
Metal blank
Metal Bluing
Metal brake pad
Metal cargo
Truck contents which include metal pipe, coils, metal fencing, ingots, steel plates, corrugated tin, and similar processed metal cargoes.
Metal catalyst
A catalyst whose active phase is supported by a metal substrate, i.e., sheet steel. Compare Metal monolith
Metal clamp
Metal conditioner
An acid-based metal cleaner that removes rust and corrosion from bare metal, etches it for better adhesion and forms a corrosion resistant film
Metal cutter
A bench tool for cutting sheet metal.

Metal fatigue
A crystallizing of the metal due to vibration, twisting, bending, etc. The unit will eventually break. Bending a piece of wire back and forth to break it is a good example of metal fatigue.


Metalflake paint
Paint that has tiny flakes, usually of bright aluminum, suspended in the liquid.
Metal folder
Metal forming
Solid metal and molten metal process such as casting, forging, stamping, and machining.
Metal halide lamp
A high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements. These lights have the best Color Rendition Index (CRI) of the high-intensity discharge lamps. They can be used for commercial interior lighting or for stadium lights.
Metal Hydride
Metal inert gas welding
Referring to or consisting of metal
Metallic drive screw
A British term for a Self-tapping screw
Metallic finish
A type of paint in which tiny flecks of shiny metal has been added in order to give a sparkle effect.
Metallic friction material
A sintered friction material formulated with metallic or metallic-ceramic materials.
Metallic lining
semi-metallic lining
Metallic paint
A Finish paint colors that contain both Pigment and small metallic flakes which reflect light. The opposite is solid paint. The flakes are often of different sizes. When the surface is viewed from different angles, the color shade seems to vary, since the flakes are all oriented at different angles in the paint and consequently reflect the light differently. Japanese motorcycles used a different size of flakes than was common in the USA. As a result, repainted tanks in the USA did not have the same look.
To coat or impregnate a metal or non-metal surface with metal, as by metal spraying or by vacuum evaporation
Metallographic examination
A test to determine the structural composition of a metal as shown at low and high magnification and by X-ray diffraction methods. Tests of this type include macro-examination, micro-examination, and X-ray diffraction analysis
Metal mesh


Metal monolith
Metal remains
Metal roller
Metal shafts
These are used to attach the connecting rods to the crankshaft. Also called eccentric journals
Metal shears
A scissor-like hand tool for cutting sheet metal. Also called snips
Metal spraying
A coating of surfaces with droplets of molten metal or alloy by using a compressed gas stream
Metal support
A thin corrugated strips of steel alloy rolled up into a tight coil as a support for the catalyst in a catalytic converter.

Forming and shaping metal
Metalworking spoon
Abbreviation for Mobile Electronics Technical Center.
  1. Use meter to refer to a measuring instrument and metre to refer to a metric distance
  2. A device for measuring the quantity of a substance passing through it.
  3. To measure with a meter.
  4. To supply at a measured rate.
Metering Circuit
Metering jet
A small hole or orifice used to control the flow of gasoline in various parts of the carburetor.
Metering orifice
A small hole that restricts the flow of liquid — usually coolant or oil
Metering port
A part of the metering unit in the fuel distributor
Metering rod
A thin, movable rod which varies the opening area in a carburetor jet. As the rod is raised it permits more fuel to enter the jet.
Metering signal
A (relative) vacuum signal generated by the pressure differential that occurs at the venturi. The strength of the metering signal determines how much fuel is pulled from the main circuit into the venturi. The smaller the venturi the greater the pressure drop and the stronger the metering signal; the larger the venturi, the smaller the pressure drop and the weaker the metering signal
Metering slits
In Bosch CIS, the narrow slits in the control-plunger barrel of the fuel distributor. Fuel flows through the slits in accordance with the lift of the control plunger and the pressure drop at the slits
Metering unit
A unit which regulates the quantity of fuel injected in the K-jetronic system. A lever connected to the sensor plate raises or lowers a stepped control plunger in the metering unit. The position of the control plunger relative to the metering ports in the metering unit varies the flow of fuel to the fuel injectors
Metering valve
  1. A valve positioned in the hydraulic line to the front brakes, on some cars with front disc and rear drum brakes. It prevents the disc brakes from applying until after the rear brake linings contact the drum. The metering valve closes off pressure to the front disc brakes until a specified pressure level is generated in the master cylinder. This allows pressure in the rear brake circuit to overcome return spring force and an gap before the hydraulic pressure is admitted to the front disc brakes
  2. A hydraulic control valve placed in the circuit to the front brakes, designed to restrict pressure to the front brake calipers until the rear brake shoes overcome the tension of the retracting spring
  3. A hydraulic valve used in some brake systems to slightly delay the application of front-disc brakes to obtain a balanced braking.
A polymer used in toughening rubber.

(CH4) A colorless, flammable, odorless hydrocarbon gas and the principal constituent of natural gas. Pure methane has a heating value of 1,012 Btu per standard cubic foot. It is colorless and naturally odorless, and burns efficiently without many by products. Local distributors add aromas as a safety measure. It is also an important source of hydrogen in various industrial processes. Methane is a greenhouse gas.
Bacteria that synthesize Methane, requiring completely anaerobic conditions for growth.
(CH3OH)A light, volatile alcohol that is occasionally blended with gasoline (typically 3%) to raise octane levels, it is poisonous to humans and causes trouble with rubber and plastic parts of the fuel system not designed to handle alcohol-blended fuels. It is typically manufactured by steam reforming natural gas. Also formed in the destructive distillation of wood. Also called methyl alcohol or wood alcohol.
Methanol blend
Mixtures containing 85 percent or more (or such other percentage, but not less than 70 percent) by volume of methanol with gasoline. Pure methanol is considered an ‘other alternative fuel’.
Methanol Fuel Cell
Bacteria that use Methane as food and oxidize it into carbon dioxide.
Methyl alcohol


Methylated spirits
Almost pure alcohol (which has wood alcohol and coloring added to make it unfit for human consumption); used for cleaning
Methyl chloroform
(trichloroethane) An industrial chemical (CH3CCl3) used as a solvent, aerosol propellant, and pesticide and for metal degreasing.
Methylcyclopentadienyl Manganese Tricarbonyl
(MMT) An organic manganese compound. It is used as a fuel additive designed to enhance octane levels in gasoline.
Methylene chloride
A colorless liquid, nonexplosive and practically nonflammable. Used as a refrigerant in centrifugal compressors, a solvent for organic materials, and a component in nonflammable paint removers.
Methyl Ester
A fatty Ester formed when organically derived oils are combined with methanol in the presence of a catalyst. Methyl ester has characteristics similar to petroleum-based diesel motor fuels.
Methyl Ether
Methyl Tertiary Butyl Ether
(MTBE) (C5H12O) A high octane, low volatility ether. It is a petroleum-based product produced from methanol and isobutylene. It is not very toxic but is not very biodegradable. The resulting ether has high octane and low volatility. It is a fuel oxygenate and is permitted in unleaded gasoline up to a level of 15% by volume.
  1. A distance of about a yard (actually a little over at 39.37′).
  2. Use metre to refer to a metric distance and meter to refer to a measuring instrument
Metric century
A bicycle ride of 100 kilometres (62.14 miles).


Metric size
Units made to metric system measurements.
Metric system
Decimal system of measuring.
Metric thread
The threads of metric nuts, bolts, and screws. Two primary styles were common ISO (International Standardization Organization) and JIS (Japanese Industrial Standard) which is no longer used. UNC thread and UNF thread cannot be interchanged with any metric nut or bolt.

Nominal diameter Width across flat Pitch
3.00 mm 5.50 mm 6.00 mm 0.50 mm 0.60 mm
4.00 mm 7.00 mm 8.00 mm 0.70 mm 0.75 mm
5.00 mm 8.00 mm 9.00 mm 0.80 mm 0.90 mm
6.00 mm 10.00 mm 10.00 mm 1.00 mm 1.00 mm
8.00 mm 12.00 mm 14.00 mm 1.25 mm 1.25 mm
10.00 mm 14.00 mm 17.00 mm 1.25 mm 1.25 mm
12.00 mm 17.00 mm 19.00 mm 1.25 mm 1.50 mm
14.00 mm 19.00 mm 21.00 mm 1.50 mm 1.50 mm
16.00 mm 22.00 mm 23.00 mm 1.50 mm 1.50 mm
18.00 mm 24.00 mm 26.00 mm 1.50 mm 1.50 mm
20.00 mm 27.00 mm 29.00 mm 1.50 mm 1.50 mm
Metric Ton
A weight measure equal to 1,000 kilograms, 2,204.62 pounds, and 0.9842 long tons.
Metro driving
An American term for driving exclusively in the city rather than on the highway. The British term is urban driving.
Abbreviation for Motor and Equipment Wholesalers Association.
Abbreviation for Multi-focal
MF headlight
A conventional headlight with a multiple-focus parabolic reflector
Abbreviation for Multiport Fuel Injection
Abbreviation for Most-Favored-Nation Treatment.


MGClick image for books on
Bend angle of a fastener shank when subjected to a MIBANT test.
Abbreviation for Morgan Impact Bend Angle Nail Tester which is the standard impact nail tester used in the pallet and lumber industry as an indication of impact bend resistance of nails or staples.
  1. Abbreviation for Mechanical Instrument Cluster
  2. Abbreviation for Microvan (e.g., Suzuki Carry).
Michelin X
Registered trademark for Michelin’s steel belted radial cord tire.
Michigan Doubles
A combination vehicle consisting of a tractor pulling two trailers with a total of 11 axles, typically for hauling gravel(dump trailers) or steel (flatbed trailers).
Mickey mouse
A trivial thing. In automotive usage it means something that is simplistic and worthless.
One millionth part of unit specified.
A pressure unit used in acoustics equal to 10-6 bar
Microbial corrosion
Corrosion associated with the action of micro-organisms present in the corrosion system
Small car, popular in the 1950s, that featured a body offering full-weather protection and mechanics often derived from motorcycle technology, e.g., Goggomobil, BMW Isetta, etc.

Microcrystalline wax
Wax extracted from certain petroleum residues having a finer and less apparent crystalline structure than paraffin wax and having the following physical characteristics: penetration at 25°C (D1321)-60 maximum; viscosity at 99°C in Saybolt Universal Seconds (SUS); (D88)-60 SUS (10.22 centistokes) minimum to 150 SUS (31.8 centistokes) maximum; oil content (D721)-5 percent minimum.
Unit of capacitor electrical capacity equal to 1/1,000,000 farad. Written mfd or μf.
A filter that removes even the smallest particles of impurities.
Micro finish
Degree of surface roughness, measured with a profilometer
Microgalvanic cell
Local cell
A small groove scribed into the surface of a solar photovoltaic cell which is filled with metal for contacts.
One millionth of an inch. Used in measuring imperfections of surface finishes. A measurement system used to express the roughness of a machined or ground surface.
  1. A precision measuring tool that will give readings accurate to 0.002 mm or 0.0001 of an inch. Sometimes called inside micrometer or outside micrometer. Also called a mike.
  2. A unit of measurement of thickness which is equal to one thousandth of a millimetre. Also called micron.
Unit of length in metric system; a thousandth part (1/1000) of one millimetre.

Micron gauge
Instrument for measuring vacuums very close to a perfect vacuum.
Micro oil filter
A special oil filter designed to trap particles down to 1 Micrometer in order to allow extended oil change intervals in the order of 60,000 miles (100,000 km) without affecting engine life
  1. Electrical component consisting of integrated circuits which may accept information, store it, and control an output device.
  2. A digital computer built on a single IC chip. It can perform arithmetic and control logic functions and is the basic component of any microcomputer system.
Microprocessor control unit
(MCU) an integral part of an electronically controlled feedback carburetor using a TWC catalyst. Various sensors monitor conditions. MCU is widely used on Ford vehicle for the control of air-fuel ratios
Microprocessor spark timing system

An overlay technique in which a machine mixes the oil and chips and then drops the mixture onto the road together. The mixture is used to fix ruts and as a surface treatment. Result offers skid-resistance for motorists.
A thin application of latex modified asphalt emulsion and sand is applied about 3/8′ to 1/2′ thick by a special truck-mounted paving system. The material sets and hardens within about one hour, and the road is then fully opened to traffic.
In dual bed catalytic converters with air injection, the plenum between the three-way catalyst and the conventional oxidation catalyst, into which secondary air is injected
Middle body
Middle distillate
A general classification of refined petroleum products in the so-called middle range of refinery distillation that includes distillate fuel oil, Kerosene, heating oil, and diesel fuels.
A chassis layout that positions the engine behind the passenger compartment but ahead of the rear axle.

Middle sill
Middle sill
That part of an automobile body to which the inner sill and outer sill are attached.
Mid-engine chassis configuration
The engine is located in the center of the chassis directly behind the passenger compartment (normally these are only 2-seater vehicles) but ahead of the center line of the rear wheels. In most cases, the fuel tank is directly in front of the passengers. This provides much better weight distribution and handling. There are three basic chassis configurations used today. The front engine configuration with the engine in the front, the passenger compartment in the middle and the trunk in the back. There are rear-engineered cars (like the Volkswagen Bug and the Porsche 911) where the trunk is in the front, the passengers are in the middle and the engine is in the back, behind the center line. And the mid-engine configuration described above.


Midgrade gasoline
Gasoline having an antiknock index, i.e., octane rating, greater than or equal to 88 and less than or equal to 90. Note: Octane requirements may vary by altitude.

The middle of the rev range, around 3000 rpm
Midrange torque
The pulling power of the engine in the middle of the rev range
At or near the middle point of a ship’s length.
Midship section
  1. A drawing showing a typical cross section of the hull and superstructure at or near amidships and giving the scantlings of the principal structural members
  2. A cross section through the ship, midway between the forward and after perpendiculars.
Mid-size car
  1. A passenger car with between 110 and 119 cubic feet of interior passenger and luggage volume.
  2. At one time (during the 1960s) a mid-size car was between the large Full-size car (like Cadillac, Lincoln, and Imperial) and the Compact cars (like Nova, Falcon, and Valiant). They included the Chevelle, Torino, and Coronet. However, with the fuel shortage of the mid-1970s, many models shrunk. For example, the full-size Mercury and Ford became about the size of the previous Torino. The Nova, et al, were called mid-sized in the ’80s, especially with the introduction of the Chevelle, Escort, and Colt. By the close of the ’80s, even Cadillac De Ville was smaller than the 1969 Chevelle.
Midsize SUV
Midsize SUVs became popular in the early 1990s as replacements for family sedans, station wagons, and minivans. There are many models of this type on the market today. The early models were based on a truck’s ladder frames and live rear axles like the Ford Bronco and GMC Jimmy and are still evident in the Toyota 4Runner and Chevrolet TrailBlazer. Many of today’s models have ironed out the stark features of those early models and have car-like characteristics.

Midsize truck-type SUV
Chevrolet TrailBlazer Dodge Durango Dodge Nitro Ford Explorer GMC Envoy
Hummer H3 Isuzu Ascender Jeep Commander Jeep Grand Cherokee Kia Sorento
Mercury Mountaineer Nissan Pathfinder Nissan Xterra Toyota 4Runner Toyota FJ Cruiser
Midsize car-type SUV
Chevrolet Equinox Chrysler Pacifica Ford Edge Ford Taurus X GMC Acadia
Honda Pilot Hyundai Santa Fe Hyundai Veracruz Mazda CX-7 Mazda CX-9
Mitsubishi Endeavor Nissan Murano Pontiac Torrent Saturn Outlook Subaru Tribeca
Suzuki XL7 Toyota Highlander
Abbreviation for metal inert gas. A term used to describe gas metal arc welding
When electrophoretic paint is attracted to car bodies when they are immersed in a bath of paint with an applied polarity across the bath and the bodies
MIG welding
An arc welding method in which the electric current is provided by the filler metal wire which is cooled and shielded from the access of air by a stream of chemically inert gas, thus preventing oxidation of the joint. Compare TIG welding
  1. A Micrometer.
  2. The use of a micrometer to measure an object.
Abbreviation for Malfunction indicator light

Mild port timing
Two-stroke engine ports open for a relatively short time, providing for a broad power band.
Mild steel
A type of steel with a low carbon content (0.1-0.25%), widely used in vehicle construction.

A distance of 1.609344 km

  1. The distance measured in miles, as by a mileometer.
  2. The total number of miles a motor vehicle has traveled.
  3. The number of miles a motor vehicle travels on one gallon of fuel.
Mileage allowance
Mileage Allowance Lease agreements usually establish the average miles per year that the car may be driven during the lease. This is often between 12,000 and 15,000 miles. The lease contract also establishes the amount you’ll have to pay for every mile driven over the allowance. This mileage fee is usually 15 cents per mile. You can often purchase additional miles at the start of the lease at a discounted rate. If you’re sure you’re going to drive more than the number of miles allowed, then your best option is to negotiate for a higher allowance on the lease.
Mileage counter
Mileage tire
Mile markers

Mile markerMile marker

Small green signs on United States highways which indicate the approximate number of miles from where the highway begins in a particular state at its most southern point (Mile zero) or at its most western point (Mile zero). The mile markers are also used to indicate exit numbers.

A device that records the number of miles traveled. Compare Odometer. Also spelled milometer.
Mile Post
A sign along the railroad or highway in the United States that indicates the distance in miles to or from a certain point.
Miles per gallon

  1. A measure of a vehicle’s fuel efficiency. It is calculated by taking the total distance in miles divided by the number of gallons of fuel to cover the distance. Making the calculation after only a single trip can be deceptive since it may be difficult to get the same full tank each time. Thus, an accurate figure can better be obtained after several trips.
  2. The EPA certification for all vehicles in the subgroup for city driving, highway driving, and a blend of the two.
Miles per hour
A rate of speed where a multiple of the distance of 1.609344 km is covered in the time of one hour

Miles per tank
A deceptive measure of a vehicle’s fuel efficiency as expressed by a distance in miles while using a portion of a tank of fuel. For example, ‘I drove to the airport and back on only half a tank of fuel.’ Both the exact distance and the actual amount of fuel are vague; but the impression is given that the vehicle gets really good miles per gallon.
Milestone Car Society
P.O. Box 50850, Indianapolis, IN, 46250.
milestone cars
As defined by the Milestone Car Society, great cars of the post-war era (1946-70) which include the following:

  • AC Ace (1954-61)
  • AC Aceca (1955-61)
  • AC Buckland Open Tourer (1949)
  • AC (Shelby) Cobra (1962-67)
  • Alfa Romeo Giuletta Spider (1956-64)
  • Alfa Romeo Giuletta/Giulia Sprint Speciale (1959-61)
  • Alfa Romeo 6C 2500 Super Sport (1949)
  • Allard Series J2, K2, K3 (1946-56)
  • American Motors AMX (1968-70)
  • Apollo GT (1963-66)
  • Arnolt Bristol (1952-62)
  • Aston Martin (1948-63)
  • Aston Martin DB4, DB5, DB6 (all) (1964-67)
  • Austin Healey 100-6 (1956-59)
  • Austin Healey 3000 (1959-67)
  • Austin Healey 100/100M (1953-56)
  • Austin/Morris Mini
  • Bentley (1946-67)
  • BMW 507 (1957-59)
  • BMW 2800/3.0 CS 68-72
  • Bugatti Type 101 (1951)
  • Buick Riviera (1949, 1963-70)
  • Buick Skylark (1953-54)
  • Cadillac Eldorado (1953-58, 67-70)
  • Cadillac Eldorado Brougham (1957-58)
  • Cadillac 60 Special (1948-49)
  • Cadillac 61 Coupe Fastback (1948-49)
  • Cadillac 62 Sedanet, Convertible DeVille (1948-49)
  • Cadillac 75 Sedan/Limo (1946-70)
  • Chevrolet Bel Air V-8 Hardtop and Convertible (1955-57)
  • Chevrolet Camaro SS/RS V-8 and Z-28 (1967-69)
  • Chevrolet Corvette (1953-72)
  • Chevrolet Nomad (1955-57)
  • Chevrolet Impala coupe and convertible (1958)
  • Chevrolet Monte Carlo SS 454 (1970-71)
  • Chrysler 300 Hurst (1970)
  • Chrysler 300 Letter Series (1955-65)
  • Chrysler Town and Country (1946-50)
  • Cisitalia GT (Pininfarina) (1946-49)
  • Cisitalia Type 202 Gran Sport
  • Citroën D8 and ID 19 (1955-64)
  • Citroen Chapron ID/DS
  • Citroen SM
  • Continental Mark II (1956-57)
  • Continental Mark III, IV, V Convt (1958-60)
  • Continental (Lehmann Peterson) Custom Limo (1963-67)
  • Continental Mark III (1969-71)
  • Corvair Monza (1960-64)
  • Corvair Monza Spyder (1962-64)
  • Corvair Monza/Corsa (1965-69)
  • Crosley Hotshot/SS (1950-52)
  • Cunningham (1951-55)
  • Daimler DE-36 Custom Built (1949-53)
  • Daimler 2.5 Special Sport Convertible (1949-53)
  • Delage D-6 Sedan (1946-49)
  • Delahaye Type 135, 175, 180 (1946-51)
  • DeSoto Adventurer (1956-58)
  • DeTomaso
  • Deutsch-Bonnet GT (panhard) 1950-61
  • Devon S/S (1958-62)
  • Dodge Coronet R/T (1967-70)
  • Dodge Charger R/T and Daytona (1968-70)
  • Dual Ghia (1956-58)
  • Excalibur II Series I (1965-69)
  • Facel Vega V-8 (1954-64)
  • Ferrari V-12 (All Front Engined) (1947-72)
  • Ford Mustang GT/GTA V-8 (1965-67)
  • Ford Mustang Boss 302/Mach 1 (1969-70)
  • Ford Crestline Skyliner (1954)
  • Ford Skyliner Retractable (1957-59)
  • Ford Crown Victoria Skyliner (1955-56)
  • Ford Sportsman (1946-48)
  • Ford Thunderbird (1955-57, 1958-60)
  • Ford Thunderbird Sports Roadster (1962-63)
  • Frazer Manhattan (1947-50)
  • Gaylord (1955-57)
  • Healey Silverstone (1949-50)
  • Hudson (All) (1948-49)
  • Hudson Hornet (1951-54)
  • Hudson Italia (1954-55)
  • Imperial (1955-56)
  • Jaguar XK 110 (1945-54)
  • Jaguar XK 120/140/150
  • Jaguar Mark V Drophead (1951)
  • Jaguar Mark VII and ’54 Mark VII M (1951-54)
  • Jaguar KX 140 (1954-57)
  • Jaguar Mark VIII (1956-57)
  • Jaguar Mark IX (1958-61)
  • Jaguar Mark X (1962-64)
  • Jaguar XK 150 (1958-61)
  • Jaguar 3.4/3.8 Sedans (1957-64)
  • Jaguar E Type (1961-67)
  • Jowett Javelin Saloon
  • Jowett Jupiter 1, 1A, R1, R4
  • Kaiser Darrin 161 (1954)
  • Kaiser Deluxe/Deluxe Virginian (1951-52)
  • Kaiser Dragon (1951-53)
  • Kaiser Manhattan (1954-55)
  • Kaiser Vagabond (1949-50)
  • Kaiser Virginian (Hardtop) (1949-50)
  • Kurtis KSC (1949)
  • Kurtis 500S/500 KK (1953-55)
  • Kurtis 500M/500X (1953-55)
  • Lagonda V-12 (1948-49)
  • Lagonda 2.5 Litre Drophead Coupe (1949-53)
  • Lamborghini Espada/Miura
  • Lancia Flaminia Zagato (1959-64)
  • Lancia Flaminia GT Two Passenger Coupe or Convertible (1961-63)
  • Lancia Flavia Coupe (1962-66)
  • Lancia Aurelia B.20 and B.2O Coupe (1951-59)
  • Lancia Aurelia B.24 Spyder and Convertible (1953-59)
  • Lea Francis 2.5 Litre Eighteen Sports (1950-54)
  • Lincoln Capri (1952-54)
  • Lincoln Continental (1946-48, 1961-67)
  • Lincoln Continental Convertible (1958-60, 1965-67)
  • Lincoln Continental Custom Limos (Lehman Peterson) (1961-67)
  • Lotus Elite (1958-63)
  • Maserati 3500/3700 GT (1957-64)
  • Maserati A6/1500, A6G/2000, A6GCS Berlinetta
  • Maserati 5000GT
  • Maserati Mexico (1958-63)
  • Maserati Ghilbi
  • Maserati Indy
  • Maserati Quattroporte (1963-69)
  • Maserati Sebring Mistral (1965-70)
  • MG Series TC (1946-49)
  • MG Series TD (1950-53)
  • MG TF/TF1500
  • MG A TwinCam
  • MG B GT V8
  • Mercedes-Benz 190 SL (1955-61)
  • Mercedes-Benz 220A Coupe and Convertible (1951-55)
  • Mercedes-Benz 220S/220SE Coupe and Convertible (1956-65)
  • Mercedes-Benz 230SL Coupe and Convertible (1963-1967)
  • Mercedes-Benz 250SE Coupe and Convertible (1965-1967)
  • Mercedes-Benz 250 SL (1965-67)
  • Mercedes-Benz 280 SL 1969-70
  • Mercedes-Benz 300 SE Coupe and Convertible (1965-67)
  • Mercedes-Benz 300 (S, SL, SE, 300 Coupe and Convertible) (1952-64)
  • Mercedes-Benz 600 (1964)
  • Mercedes-Benz SWB-LWB 600 (1965-70)
  • Mercedes-Benz 300 Non-Unitized Body (1951-63)
  • Mercedes-Benz SEL 6.3
  • Mercury Cougar XR-7 (1967-68)
  • Mercury Sportsman (1946)
  • Mercury Sun Valley (1954-55)
  • Morgan Plus Four (1950-64)
  • Morgan 4/4 (1955-70)
  • Muntz Jet (1950-54)
  • Nash Healey (1951-54)
  • NSU Wankel Spyder (1964)
  • OSCA MT-4 (1948-56)
  • Oldsmobile 88 (Coupe, Convertible, Holiday) (1949-51)
  • Oldsmobile 98 Holiday HT (1949)
  • Oldsmobile Fiesta (1953)
  • Oldsmobile 442 (1964-71)
  • Oldsmobile Toronado (1966-67)
  • Packard Caribbean (1953-56)
  • Packard Custom (Clipper and Custom Eight) (1946-50)
  • Packard Pacific/Convertible (1954)
  • Packard Panther Daytona (1954)
  • Packard Patrician/400 (1951-56)
  • Panhard Dyna (1946-67)
  • Pegaso (All) (1951-58)
  • Plymouth Fury (1956-58)
  • Plymouth Satellite SS and GTX (1965-70)
  • Plymouth Barracuda Formula S (1965-69)
  • Plymouth Roadrunner and Superbird (1968-70)
  • Plymouth Sport Fury Coupe and Convertible (1959)
  • Pontiac Safari (1955-57)
  • Pontiac GTO (1964-69)
  • Pontiac Trans AM 400-455 HO (1970-72)
  • Porsche Series 356 (1949-64)
  • Porsche 356C (1965)
  • Porsche 911 E, L, S&T Coupe/Targa (1964-72)
  • Riley 2.5 (RMA, RME) (1945-55)
  • Rolls-Royce (All) (1947-67)
  • Rover
  • Shelby 350GT and 500 GT (1965-70)
  • Sunbeam Tiger Convertible (1965-67)
  • Studebaker Avanti (1963-64)
  • Studebaker Gran Turismo Hawk (1962-64)
  • Studebaker Starlight Coupe (1947-49)
  • Studebaker Starliner Hardtop (Six and V-8) (1953-54)
  • Studebaker President Speedster (1955)
  • Talbot Lago 4.5 (All) (1946-54)
  • Toyota 2000 GT (1966-70)
  • Triumph TR2/TR3 (1953-63)
  • Tucker (1948)
  • Volvo P.1800S, 2-door Coupe (1961-72)
  • Willys Overland Jeepster (1948-51)
  • Woodill Wildfire (1952-58)
Military use
Includes sales to the Armed Forces, including volumes sold to the Defense Fuel Supply Center (DFSC) for use by all branches of the Department of Defense (DOD).
Milk run
A bus route with frequent delivery stops
  1. Often used to refer to the whole engine.
  2. To remove metal through the use of a rotating toothed cutter.
  3. To grind, press or reduce to powder.
  4. To shape or cut metal.
  5. A Milling cutter
  6. A Milling machine
Milled from bar
A fastener made on a screw machine or lathe by cutting material away from the original piece of metal. It is used for manufacturing very large diameters which cannot be cold formed and for small quantities where it would not be economical to set up cold forming equipment. However, machining can interrupt the grain of metal causing a lessening in tensile and fatigue strength. Also called machining.
Milled glass fiber
Chopped strands of glass fibre which vary in length from 3 mm to about 50 mm
Mille Miglia
(MM) A one thousand mile Italian road race that took place from 1927 to 1957.
Miller cycle
A type of engine developed by Ralph Miller in the 1940s. It differs from a standard engine in that it has a supercharger. During the compression stroke, the intake valve remains open so that compression is against the supercharger instead of against the walls of the cylinder. The efficiency of the engine is increased by up to 15%.
Combining form denoting one thousandth (1/10001; for example, millivolt means one thousandth of a volt.
One thousandth of an ampere. With figures it is usually written mA
An ammeter with a milliampere scale
A unit of measurement of weight. A thousand milligrams equal one gram. With figures usually written mg
See Millilitre
A unit of measurement of liquid or volume where a thousand millilitres equal one litre. Also, one millilitre equals one cubic centimetre. With figures usually written ml. The American spelling is milliliter.
A unit of measurement of distance where a thousand millimetres equal one metre. 25.4 millimetres equal an inch. With figures usually written mm. American spelling is millimeter; however in the rest of the world, the ending ‘meter’ refers to a measuring instrument (e.g., speedometer, tachometer) while ‘metre’ refers to a metric measurement (e.g., kilometre, centimetre).
American spelling of millimetre. A metric measurement equivalent to about 0.039370 of an inch.
Milling cutter
A rotating, toothed cutter in a Milling machine, used to cut or shape metal
Milling machine
  1. A machine that uses a variety of rotating cutter wheels to cut Splines, gears, Keyways, etc.
  2. A machine tool with a table on which rests material which is cut by a rotating cutting tool held by a horizontal arbor or vertical spindle
Milling Process
A machining process whereby a surface is generated with a rotating toothed cutter. Each tooth takes an individual chip.
Millsaw file
A flat hand file with round or square edges for sharpening saw blades or machine-cutting knives
A device that records the number of miles traveled. Compare Odometer. Also spelled mileometer.
Abbreviation for Mechanic Installed Market.
Mine Drainage
Any of the various naturally occurring inorganic substances, such as metals, salt, sand, stone, sulfur, and water, usually obtained from the earth. Note: For reporting on the Financial Reporting System the term also includes organic non-renewable substances that are extracted from the earth such as coal, crude oil, and natural gas.
Mineral oil
A light lubricating oil refined from crude oil
Mineral soil
Organic-free soil that contains rock less than 2 inches in maximum dimension.
A vehicle brand of which all 1925-48 models except 4-cyl are classic car.
A small British front-wheel drive car designed in 1959 by Sir Alec Issigonis (1906-88). Current model is the Cooper (2002-07). Also spelled MINI.
Miniature offset open-end wrench
A very small, open-ended wrench with two jaw openings of the same size set at different angles to the handle, e.g., 15° at one end and 60° at the other. Also called Electrical wrench
Small, single-decker bus designed to carry around 12-20 people
A very small sedan carrying no more than four adults
Mini catalytic converter
A small but usually a primary catalytic converter which is installed close to the engine in the headpipe
A true magnesium wheel, developed for the Mini in 1962 by nuclear engineer Derek Power on the basis of experience gathered with magnesium components in nuclear power plants. The Minilite started the boom in alloy wheels
Minilite alloy wheel
A true magnesium wheel, developed for the Mini in 1962 by nuclear engineer Derek Power on the basis of experience gathered with magnesium components in nuclear power plants. The Minilite started the boom in alloy wheels
Minimum ignition Time
The minimum allowable time for the specified function of any device.
Minimum stable signal
(mss) Correct setting for an expansion valve where it is using the evaporator efficiently but remains free from hunting.
Mini spare wheel
Minimum thickness
The least amount of thickness to which a brake disk can be machined or worn before it becomes unsafe. This dimension is usually stamped or cast into the disc.
Mini tube cutter
A compact tube cutter for cutting brass, copper, plastic, or thin steel tubing in confined areas
  1. Minibus-sized van with no side windows, used to transport goods instead of people.
  2. Although the smaller van, with windows, was available from VW and its GM copy Greenbrier (based on the Corvair), the term was not known until 1983 when Chrysler produced its Magic Wagon series (later copied by GM and Ford) which has almost eliminated the station wagon.
A mineral-fiber-reinforced polyamide, used for alloy wheels as a rim trim cover that protects the balancing weights
Min/max governor
Controls the idle speed and prevents overspeed
Minor diameter
  1. The inside or smallest diameter of the screw threads.
  2. The diameter measured from the thread valley to the corresponding valley on the opposite side of the bolt or screw
  3. On a straight thread, the minor diameter is the diameter of the coaxial cylinder which would pass through the roots of an external thread.
Minority carrier
A current carrier, either an electron or a hole, that is in the minority in a specific layer of a semiconductor material; the diffusion of minority carriers under the action of the cell junction voltage is the current in a photovoltaic device.
Mint condition
A colloquial term for a vehicle that has been kept in, or restored to, perfect condition. Also called cherry condition.
A reflective device which is located in one of several positions between the two A-posts within the passenger compartment (called the Rearview mirror); behind either/both sunvisors (Vanity mirror); on either side of the outer A-posts; on the forward or leading edge of the front Doors; or on the front Fenders.

Mirror control
  1. General term referring to all types of frame damage caused by accidents.
  2. The condition of two mating parts which are not placed in proper alignment
Abbreviation for Microprocessed Sensing and Automatic Regulation (GM)
Miscellaneous petroleum products
Includes all finished products not classified elsewhere (e.g., petrolatum lube refining byproducts (aromatic extracts and tars), absorption oils, ram-jet fuel, petroleum rocket fuels, synthetic natural gas feedstocks, and specialty oils).
Substances that are capable of being mixed.
The failure of the fuel charge in one or more engine cylinders to fire or ignite at the proper time. It can be due to poor compression caused by worn or improperly adjusted valves, worn piston rings, a faulty Head gasket, or in the case of a two-stroke engine leaking crank seals. It can also be caused by poor Ignition due to worn or dirty spark plug electrodes, worn or improperly gapped points or spark plugs, poor fuel delivery, faulty ignition wiring, or faulty distributor components. An easy way to detect the problem is to put a stiff piece of paper at the end of the Tail pipe and listening for an irregular puffing sound. Also called missing or backfiring.
Failure of an explosive to occur in one or more cylinders while engine is running. This may be a continuous or intermittent failure




Mist action
An action of intermittent wipers which will make one or two swipes to clear away any mist from the windshield.
Mist coat
Usually the final color Coat, produced by over-reducing with a slow evaporating Thinner. It is generally used to blend in the final Overlap areas.
The fog sometimes produced during adhesive, coating, or sealer spray application is usually caused by excessive atomizing pressure. Most common when spraying water-dispersed products of very thin consistency or slow drying materials such as diluted house paint.
MitsubishiClick image for books on

A model of automobile manufactured in Japan by the Mitsubishi Motors and includes 3000GT (1991-99), Aspire (1999-2003), Cordia (1982-90), Diamante (1992-2004), Eclipse (1990-2008), Endeavor (2004-07), Expo (1992-95), Galant (1969-1975), Galant Sigma (1976-90), Galant Eterna (1987-98), Grunder (2004-current), Lancer (2002-08), Legnum (1999-2003), Minivan (1988-90), Mirage (1978-2002), Montero (1982-2006), Montero Sport (1997-2004), Outlander (2003-07), Pickup (1988-96), Precis (1985-94), Raider (2006-07), Sigma (1989-90), Starion (1982-90), and Tredia (1982-90)

Refers to the combination of light, medium and heavy density freight.
Mix air cap
Mixed-flow impeller
A pump impeller which combines radial and axial-flow principles, i.e., liquid flows both along the drive shaft and out through the impeller; pump impellers are classed as mixed-flow when the specific speed is 2,000 to 6,000 rpm
Mixed-flow pump
A centrifugal pump which develops its head partly by centrifugal force and partly by the lift of the vanes on the liquid
The combination of Mixer head, Mixer throat, and Mixer tube

Mixer face
The air inlet end of the mixer head.
Mixer Head
The portion of an injection (Bunsen) type burner, usually enlarged, into which primary air flows to mix with the gas stream.
Mixer Throat
The portion of the mixer which has the smallest cross-sectional area and which lies between the mixer head and the mixer tube.
Mixer Tube
The portion of the mixer that lies between the throat and the burner head.
Mixing chamber
  1. That part of the welding torch where the welding gases are intimately mixed, prior to combustion.
  2. That part of a carburetor distinct from the float chamber both in function and layout, in which the air and the fuel mix as they meet.
  3. The Midbed of a catalytic converter
Mixing head
The head of an oxyacetylene torch by which the mixture of oxygen and acetylene can be adjusted
Mixing rolls
A machine designed for the mixing and Mastication of the materials from which tires are made
Mixing Well
Trucker slang for a highway cloverleaf as in ‘You got a parking lot on the mix-master up ahead.’
Mixte frame
A bicycleframe that replaces the Top tube with twin lateral tubes that run all the way from the Head tube back to the rear Dropouts.
  1. A substance made up of two or more chemicals in some proportion.
  2. A fuel-air mixture in an internal combustion engine.
  3. The combination of oil and gasoline in the fuel tank of a two-stroke engine, e.g., 150, i.e., one part of oil is added to every 50 parts of fuel.
Mixture Control
Mixture control knob


Mixture control screw
Mixture control solenoid (M/C Solenoid)
  1. A device, installed in carburetor, which regulates the air/fuel ratio by oscillating the metering rods.
  2. A computer-controlled device in a feedback carburetor that alters the mixture adjustment by moving the carburetor’s metering rod in and out of the metering jet. Also called a Duty-cycle solenoid
  3. An electronically controlled device which regulates bleed air, fuel, or both, on carbureted vehicles.
Mixture control unit
  1. A unit in the K-jetronic fuel injection system which combines the fuel distributor and the airflow sensor; it monitors the rate of airflow and meters the fuel supplied to the injectors.
  2. In Bosch CIS, the collective term for the airflow sensor plate and the fuel distributor, which are integrated into a single component
Mixture discharge nozzle
Mixture screw
Mixture volume
The quantity of air/fuel mixture
Abbreviation for Maintenance Local Improvement District.
ML oil
Motor Light oil used in engines that work under ideal conditions of light loads, moderate speeds, and clean conditions.
Abbreviation for Manual Lever Position
Abbreviation for Modulated Lock Up Solenoid or its Control Circuit (Ford)
Abbreviation for Manual Valve Lever Position
  1. Abbreviation for millimetre. 25.4 mm = 1 inch.
  2. Abbreviation (MM) for Mille Miglia which is a one thousand mile Italian road race that took place from 1927 to 1957.
Abbreviation for Magnetomotive force
MM oil
Motor Medium oil used in engines that work under moderate conditions where there is moderate loads, occasional high speeds, and a normal amount of dust.
Methylcyclopentadienyl Manganese Tricarbonyl.
Mobile home
A large home which can be hauled to its location (it does not have an engine). Once in place, the wheels are removed. In most cases, the home is never moved again. A Motor home, in contrast, keeps its wheels and has its own engine.
Mobile phone
A Cellular telephone (i.e, cell phone)
Mobile Sources
Mobile two-way radio
A receiver/transmitter used for CB communication
mobility scooter
Mobility scooter
Mobility Scooter
A small three or four wheeled vehicle designed for a disabled person and is usually powered by two 12-volt batteries (producing 24 volts).
Move personnel, equipment, supplies, and incidentals to the project site. Establish offices, buildings, and other facilities necessary for work on the project.
  1. A full-size model of a vehicle made of wood and clay, used for design studies.
  2. A representation, usually of the final shape of a styled or engineered body. Can be made of wood, fiberglass, metal or any combination.


  1. A full-size model of a vehicle made of wood and clay, used for design studies.
  2. A representation, usually of the final shape of a styled or engineered body. Can be made of wood, fiberglass, metal or any combination.


  1. A way of operating.
  2. A particular state of operation.
Mode door
A device which directs the flow of air through the heater/evaporator box
  1. A vehicle can be designated by a number of parameters manufacturer, make, model, series, engine size, etc. For example GM, Cadillac, DeVille, Concours, Northstar 4.6 engine.
  2. A miniature representation of a full-size vehicle.
Model A
Ford Model AClick image for books on
Ford Model A

A designation used by a number of vehicle manufacturers to indicate the first model offered, the most noteworthy is the Ford Model A which is actually newer than the Model T it replaced.

Model designation
A shortened description of a particular model
Model line
A group of motor vehicles having the same platform or model name.
Model name
word, group of words, letter, number or similar designation assigned to a motor vehicle by a marketing division of a motor vehicle assembler.
Model T
Ford Model TClick image for books on
Ford Model T

An early model of automobile manufactured by Ford and replaced by the Model A

Model year
(MY) A new model year starts after the summer break of the car production plant, during which the assembly lines are altered to accommodate the changes introduced in the cars of the next model year. A model year and year of manufacture can, therefore, differ.
Modified car
A class of vehicle built during 1950-1973 with modern technology, equipment, or refinements and with some modifications to the body.

Abbreviation for modifications to refer to changes made in the appearance or performance of a vehicle.
Modular air strut
Modulated EGR
Modulated valve
Type of device or control which tends to adjust by increments (minute changes) rather than by either full on or full off operation.
Modulating combustion controls
The action of a combustion control which gradually varies the air and fuel supplies within limits in accordance with load demand.
Modulating refrigeration cycle
Refrigerating system of variable capacity.
Modulating valve
A valve designed so the valve opening is controlled within narrow limits throughout the entire range from the full open to the closed position.
Variation of a wave.

Modulation Valve
  1. A pressure control or adjusting valve used in the hydraulic system (i.e., Hydraulic modulator) of the automatic transmission. When the vehicle is under heavy load or full throttle, the modulator increases the pressure to hold the clutches in place. In a light load situation, the modulator reduces pressure to give smoother shifts. If the vehicle tends to stay in Low gear, shifts with difficulty, or produces a white smoke, and has low Transmission fluid or has leaked Transmission fluid, you have a transmission problem. It may be cured by an expensive repair or by simply replacing the modulator. Also called Vacuum modulator.
  2. The unit in a wheel slip brake control system which adjusts brake actuating force in response to input signals.
Modulator pressure
Pressure controlled by the actuator valve and thus directly related to inlet manifold vacuum
Modulator valve
A valve operated by the modulator to create modulator pressure by means of inlet manifold vacuum

  1. A self-contained unit that serves as a building block for the overall structure of something.
  2. A packaged functional assembly of wired electronic components for use with other such assemblies.
  3. An electronic control unit, amplifier or igniter of solid state or integrated design which controls the current flow in the ignition primary circuit board on input from the pick-up coil. When the module opens the primary circuit, the high secondary voltage is induced in the coil
  4. A series of photovoltaic cells or an assembly of cells into panels (modules).
Modulus in shear
A measure of a material’s resistance to shearing stress equal to the shearing stress divided by the resultant angle of deformation expressed in radians
Moisture content
The water content of a substance (a solid fuel) as measured under specified conditions being the dry basis, which equals the weight of the wet sample minus the weight of a (bone) dry sample divided by the weight of the dry sample times 100 (to get percent); wet basis, which is equal to the weight of the wet sample minus the weight of the dry sample divided by the weight of the wet sample times 100.
Moisture indicator
Instrument used to measure moisture content of a refrigerant.
  1. A hollow form, matrix, or cavity, into which molten metal or plastic is poured to form a casting or product in the desired shape.
  2. A device, that includes a matrix, enclosing the tire and supplying heat and pressure to cause curing.
  3. To shape something into the desired form.
  4. A light pattern of a part of a ship usually made of thin wood or paper. Also called a template.
The capacity for being molded into a particular form
Mold bonded linings
Brake pad linings with the friction material cured in place on a backing plate drilled to provide physical engagement. A bonding adhesive is also used between the backing plate and the lining.
Molded beam
The maximum breadth of a hull measured between the inboard surfaces of the side shell plating of flush-plated ships
Molded depth
The vertical distance from the molded baseline to the top of the freeboard deck beam at side, measured at midlength of the ship
Molded Linings
Molded part
A plastic part produced by injection molding etc.
Molded seat
  1. A plastic part produced by injection molding etc. Moldings are parts which have been produced from molding materials (compounds) by shaping in molds closed on all sides (e.g., by compression molding, transfer molding, or injection molding).
  2. An applied, raised strip, sometimes to cover a joint between body panels or in later cars pressed in for ornamentation.
Molding compound
Molding machine
Molding material
Molding materials are products which can be molded permanently by a shaping process employing mechanical forces within a given temperature range into molded parts or semi-finished articles; in some cases molding materials are used in a preformed state (e.g., pelleted or granulated) without their plastic moldability being appreciably impaired by such preforming
Mold loft
  1. A floor space used for laying down the full size lines of a ship for making templates for construction
  2. A shed or building with large, smooth floor on which the lines of a ship can be drawn to full scale.
Mold shrinkage
In thermoplastics, the difference in dimension between the cold mold and the cooled molded part, expressed in percent relative to the dimension of the cold mold
The quantity of a compound or element that has a weight in grams numerically equal to its molecular weight. Also referred to as gram molecule or gram molecular weight.
Molecular weight
The mass of a molecule that may be calculated as the sum of the atomic weights of its constituent atoms
The smallest portion of an element or compound that still retain all the properties of the original matter when it is divided. For example water is still composed of two parts hydrogen and one part oxygen no matter how small the drop of water is. Once the element hydrogen or oxygen is removed from water, the result is no longer the compound water.
Mole grips
Locking pliers
Mole wrench
Locking pliers
Mollier’s diagram
Graph of refrigerant pressure, heat, and temperature properties.
Molten carbonate fuel cell
(MCFC). A type of fuel cell consisting of a molten electrolyte of Li2CO3/Na2CO3 in which the species CO3 2- is transported from the cathode to the anode. Operating temperatures are typically near 650°C
Abbreviation for molybdenum which is a lightweight metal which is often combined with chromium. It is used in Piston rings (chrome moly rings) and even bicycleframes (chrome moly frames).
A hard white metallic element (symbol Mo; atomic number 42; atomic mass 95.94) which forms hard steel and/or chromium alloys to make piston rings and bicycleframes.

Molybdenum piston ring
A piston ring with a molybdenum coating
Moly ring
A piston ring with a molybdenum coating
Momentary speed changes
Short-lived speed changes which occur in a generator immediately after a sudden change in load. Also called transient speed changes.
Moment Diagram
Moment of inertia
This is similar to inertia except that it relates to rotating movement rather than linear movement. Linear movement is the tendency of an object to remain motionless if at rest and to keep moving in a straight line if already in motion. The moment of inertia, however, is the tendency of an object to resist being accelerated when it is rotating. The polar moment of inertia is the rotating movement around a vertical axis through the center of rotation. It greatly affects steering and handling response in an automobile. The greater the length of the axis the greater the polar moment of inertia. By having the heavy components of a vehicle such as the engine and transmission between the two front wheels, the polar moment of inertia is low so that the tires can easily change the direction of the vehicle.

A measure of a body’s motion. It can be calculated from the product of the body’s mass and velocity.
Abbreviation for Motor Octane Number.

Monel metal
Corrosion resistant alloy of nickel, copper, iron, and manganese (usually two-thirds nickel and one-third copper) invented by the International Nickel Co. It has good strength, excellent corrosion resistance against salt water and in high temperatures, and is very expensive.
Money factor
  1. When purchasing a vehicle, the characteristics of its engine, appearance, and appointments may be very appealing, but the money factor (i.e., its cost) may be prohibitive.
  2. The most common way to express the base interest rate of a lease is as a money factor. If you multiply a money factor by 2400, the result will be equivalent to the base interest rate. The money factor of most leases is known by a dealer’s sales staff. The money factor measures the cost of money, just like an interest rate. However, money factors are used almost exclusively in leases, whereas interest rates are used everywhere else.
Money metal
Corrosion-resistant alloy of nickel, copper, iron, and manganese
Diagnostic routines programmed into the PCM. The PCM uses these programs to run diagnostic tests, and to monitor operation of the vehicle’s emissions-related components or systems to ensure they are operating correctly and within the vehicle’s manufacturer specifications. Currently, up to eleven monitors are used in OBD II systems. Additional monitors will be added as the OBD II system is further developed. Not all vehicles support all eleven monitors.

Maintaining a continuous control of an operation or function, varying control as required by specific conditions
Monitor System
Monkey wrench
A tool which is similar to a pipe wrench. While a pipe wrench has teeth and a loosely mounted head that allows it to bite into the pipe and tighten as a strain is put on the handle, a monkey wrench has adjustable, smooth jaws that always remain parallel. The money wrench is used for turning pipe unions, the heads of bolts, and other flat surfaced object. The monkey wrench has pretty much been replaced by the Crescent wrench and other more modern adjustable wrenches. Monkey wrenches are still used on old steam engines (not necessarily locomotives) and boiler fittings. Some call it a steamboat wrench. (definition submitted by George King III). The expression throw a monkey wrench into something generally means to sabotage something or to cause a problem or delay in performing repairs.

All the cylinders cast as one unit.
Monobloc casting
A type of engine construction where the cylinders are cast in a single block which incorporates the crankcase
Monobloc construction
A type of engine construction where the cylinders are cast in a single block which incorporates the crankcase
All cylinderscast as one unit.
Refrigerant better known as Freon 22 or R-22. Chemical formula is CHCIF2. Cylinder color code is green.
Of a single color.
  1. A design of a vehicle’s body where a single shell has the engine and suspension attached to it in various places to spread the load evenly over the whole shell. Holes are cut only to install the engine and allow the driver to get into it. Otherwise it is completely closed. Also called unit or unitized construction or unitary construction.
  2. A motorcycle frame in which the structure is made as one unit from a sheet material (i.e., alloy or steel). It may also include bodywork or fuel containers in the structure. The Vespa scooter and the F750 Norton of c.1973 are among the rare examples in motorcycles
Monodex-type cutter


A single point injection system developed by Bosch
A single block of material; used to describe the (ceramic) base for the catalyst in one type of catalytic converter.
Monolithic converter
Catalytic convener with a catalyst-coated, ceramic honeycomb monolith through which the exhaust gases pass
Monolithic substrate
The ceramic honeycomb structure as a base to be coated with a metallic catalyst material for use in the catalytic converter
A relatively simple compound which can react with itself to form a polymer or with other monomers to form a copolymer
Monotube damper
Monotube shock absorber
Monroney sticker
A window sticker. A US federal law requires that all cars sold in the USA display a Monroney sticker which is required to specify the manufacturer’s suggested retail price for the vehicle and all its factory-installed options, a destination charge for shipping from final assembly point (or port of importation) to the dealer, and EPA fuel economy estimates; most dealers add a second window sticker that lists accessories installed at the dealership, as well as other charges
A type of vehicle, usually a truck, which has very large tires.
Monte Carlo
Monte CarloClick image for books on
Monte Carlo

A model of car produced by the Chevrolet division of General Motors from 1970 to 2007

Monthly payment
  1. The amount that must be paid each month to satisfy the lease contract. It is common for the monthly payment shown in lease advertisements to exclude applicable taxes, which will add to the amount paid each month.
  2. The amount that is paid on a vehicle loan.
MontrealClick image for books on

A model of automobile from Alfa-Romeo

Montreal Protocol
The Montreal Protocol on Substances that Deplete the Ozone Layer (1987). An international agreement, signed by most of the industrialized nations, to substantially reduce the use of chlorofluorocarbons (CFCs). Signed in January 1989, the original document called for a 50-percent reduction in CFC use by 1992 relative to 1986 levels. The subsequent London Agreement called for a complete elimination of CFC use by 2000. The Copenhagen Agreement, which called for a complete phaseout by January 1, 1996, was implemented by the U.S. Environmental Protection Agency.
  1. An automobile make of which only the Custom bodies with required application are classic cars.
  2. A type of Hubcap which does not cover the whole wheel and is perfectly smooth and dome shaped.
Moon key
Securing a ship at a dock or elsewhere by ropes or cables
Mooring line
A cable or rope used in securing a ship
Mooring Pipe
A casting which prevents chafing of mooring lines passing through bulwark plating.
Abbreviation for Maximum operating pressure
Trade name of Chrysler Corp for its motor parts (i.e., MOtorPARts). Chrysler also uses the name Autopar to indicate its automobile parts (i.e., AUTOmobilePARts).
A two-wheeled motorized bicycle (short for motorized pedal bicycle) with an engine of less than 50cc or an electric motor. It must have a maximum speed of 45km/h. It must also have pedals which can propel it in the event that the motor does not work or needs assist. In some instances, the operation of the pedals is necessary to start the motor. Similar units without the pedals are called scooters
A thick, velvety upholstery fabric often used as weatherstrip
MorganClick image for books on

A vehicle brand of which the 1950-64 Plus Four models are milestone cars.

MorrisClick image for books on

A model of automobile manufactured in England

Morris Garages


Most-Favored-Nation Treatment
(MFN) one country’s commitment to extend to another country the lowest tariff rates that it applies to any third country.
Abbreviation for the British Ministry of Transport
MOT certificate
A certificate awarded when a vehicle passes an MOT test
A substance that was used to increase the octane rating in gasoline. It had a marginal effect in increasing octane.
Mother-in-law seat
A single rear seat that faces to the side (instead of the front) and is usually found in coupes or cabriolets.
A repeated pattern or theme.
Motion Machine
Motion shaft
Off-road racing over a rough circuit. Formerly known as scrambling

MotoguzziClick image for books on

A motorcycle manufacturer

  1. An electrically driven power unit (electric motor). This term is often incorrectly (but commonly) applied to an internal combustion engine.
  2. Rotating machine that transforms fluid or electric energy into a mechanical motion.
  3. An engine
  4. An automobile.
  5. Attaching a Generator to a battery in such a way it revolves like an electric motor.
  6. A starting motor, i.e., starter.
  7. To travel by automobile, as in ‘Let’s motor down the road.’
Motor Association
A motorcycle.
Motor burnout
Condition in which the insulation of an electric motor has deteriorated (become poor in quality) due to overheating.
Motor capacitor
Single-phase induction motor with an auxiliary starting winding connected in series with a condenser (capacitor) for better starting characteristics.
Motor car
A British term for a car or automobile (a 4-wheel road vehicle)
Motor caravan
A British term for Motor home
Motor Carrier
Motor carrier act of 1935
Act of U.S. Congress bringing motor common and contract carriers under ICC jurisdiction.
Motor carrier act of 1980
Act of Congress that deregulated for-hire-trucking.
Motor Carrier Advisory Committee
An organization that reviews regulations, statutes and general issues relating to motor carriers and advises the transportation department and staff.
Motor city
Trucker slang for Detroit, Michigan.
Motor control
  1. Device to start and/or stop a motor or hermetic motor compressor at certain temperature or pressure conditions.
  2. Temperature or pressure-operated device used to control running of motor.
A two-wheeled motorized vehicle where the two wheels are not side-by-side but in line. Most have the fuel tank ahead of the saddle and the engine just below the tank. The engine size usually ranges from 50cc to 1500cc. Also called motorbike or just bike.

The author’s web site that created this dictionary
Motor, four-pole
1800 rpm, 60 Hz electric motor (synchronous speed).
Motor Gasoline
A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, that have been blended to form a fuel suitable for use in spark-ignition engines.
Motor gasoline blending
Mechanical mixing of Motor gasoline blending components, and oxygenates when required, to produce finished motor gasoline. Finished motor gasoline may be further mixed with other motor gasoline blending components or oxygenates, resulting in increased volumes of finished motor gasoline and/or changes in the formulation of finished motor gasoline (e.g., conventional motor gasoline mixed with MTBE to produce oxygenated motor gasoline).
Motor gasoline blending components
Naphthas (e.g., straight-run gasoline, Alkylate, Reformate, Benzene, Toluene, Xylene) used for blending or compounding into finished motor gasoline. These components include reformulated gasoline blendstock for oxygenate blending (RBOB) but exclude oxygenates (alcohols, ethers), Butane, and Pentanes plus. Note: Oxygenates are reported as individual components and are included in the total for other hydrocarbons, hydrogens, and oxygenates.
Motor Gasoline Prices
Motor grader
A Bulldozer with a blade able to be set in such a way to push material to the side of the road. Usually called a Grader or Angledozer
A motorized recreational vehicle that looks something like a bus.

Motor insurance
Insurance against damage to or damage caused by a vehicle.

Someone who drives an automobile
A wheeled vehicle with a motor or engine.
Motorized Pallet Truck
There are two different types of motorized pallet trucks, the Walkie and the Rider. The Walkie is built so that the operator can walk alongside it. The Rider is built so that the operator can stand and ride on the truck.
Motor mechanic


Motor mount
The rubber-covered bracket that hold the engine and transmission to the frame of the vehicle and cushions vibrations.
Motor Octane
The octane as tested in a single-cylinder octane test engine at more severe operating conditions. Motor Octane Number (MON) affects high-speed and part-throttle knock and performance under load, passing, climbing and other operating conditions. Motor octane is represented by the designation M in the (R+M)/2 equation and is the lower of the two numbers.
Motor octane number
(MON) A value of octane as measured under more severe conditions and is most important for octane satisfaction at wide open throttle.

Motor oil
Engine oil or gear oil
Motor oil classification
The API classification system for the designation of gasoline and diesel engine oils, which reflects the quality, performance, and suitability of the oils for various engines. The S classification was for gasoline engines while the C classification was for diesel engines.

Motor pump
Motor Resistor
Motor scooter
A lightweight motorcycle with small wheels, an enclosed engine, open foot platform, and leg shields. Also called scooter.
Motor speed
The number of revolutions that the motor turns in a given time period (i.e. revolutions per minute, rpm).
Motorsports Association
Motor starter
High-capacity electric switches usually operated by electromagnets.
Motor stator
Stationary part of electric motor.
Motor, two-pole
3600 rpm, 60 Hz electric motor (synchronous speed).
Motor types
Electric motors are classified by operating characteristics and/or type of power required. Induction motors include single-phase and three-phase motors. Direct-current motors are further classified as shunt, series, and compound.
Motor valve
An electric control valve that is automatically closed by a spring or other mechanical means in the event the electric circuit is broken.
Motor vehicle
Any automotive vehicle that does not run on rails; usually with rubber tires; such as cars, vans, trucks, lorries, scooters, and motorcycles

Motor vehicles cargo
Truck carrying motor vehicles capable of at least 40 MPH on-highway, carried such that no wheels touch the road. These will probably be on flatbed trucks and trailers or on auto-carriers.
Motor Vehicle Safety Act
(MVSA) Act which regulates the manufacture and importation of motor vehicles and motor vehicle equipment to reduce risk of death, injury and damage to property and the environment.
  1. A British term for a multi-lane, main road for fast-moving traffic with speeds from 90 – 110 kmh
    • has a center median
    • limited access (i.e., few exit and entry points)
    • Called M road.
Motor wheel type
(Spoke steel type) — A type of dual mounting wheels similar to the Chevrolet type using single cone locking nuts on each stud, however, the conical washer which forms the base of the cone is loosely attached to the nut and swivels independently.
Bosch term to denote its engine management systems. The original Motronic system combined L-Jetronic with electronic ignition timing control in one control unit. Most Motronic-equipped engines also have electronic idle stabilization. Around 1986, Motronic system got knock regulation by ignition timing of individual cylinders; adaptive circuitry, which adapts fuel delivery and ignition timing to actual conditions; diagnostic circuitry which enables the control unit to recognize system faults and store fault information in its memory. Motronic has also been integrated with KE-Jetronic system and is referred to as KE-Motronic
MOT test
An annual roadworthiness test for all vehicles in Britain over two years old, undertaken by a garage approved by the (currently named) Department of Transport. Parts covered by the MOT test are steering, suspension, transmission, lighting, brakes, tires and wheels, seat belts, horn, exhaust system (including a metered emission check), and vehicle structure
Spotty, non-uniform, blotchy appearance of metallic paint, characterized by small, irregular areas darker in color, or spots in solid color paint — caused by the flakes flowing together
British term for mold
British term for Moldability
Moulded part
British term for Molded part
British term for Molding
Moulding material
British term for Molding material
Mould shrinkage
British term for Mold shrinkage
Moulton Hydragas suspension
Hydropneumatic suspension developed by Leyland
Moulton Hydrolastic suspension
Hydrolastic suspension developed by Leyland
  1. To attach something to a support.
  2. A device for attaching something.
Mountain bike
A bicycle with straight handlebars, sturdy fat tires, and Wide-range gearing designed for off-road use. Also called All-Terrain Bike or ATB.
Mountain tire
A tire used on a mountain bike which is 26 in. and generally available in widths from 1 inch to 2.2 inches.
Mountain wheel
A 26 in. wheel consisting of a hub, rim, and spokes.
Mounted speaker
A support to which or by means of which something is attached.

Mounting bolt
A bolt upon which some component is secured.


Mounting box
Mounting Bracket
Mounting face
Mounting flange
Mounting frame
A floating-frame disc brake in which the floating frame is held by a casting which is bolted to the steering knuckle or other suspension part
Mounting panel
Abbreviation for Microprocessor Vehicle Actuation
Move off
To start from rest; to begin to drive away
Moving contact
A component of a solenoid switch; in a starter motor it is designed for switching on the electric circuit in the excitation and armature windings.
Abbreviation for Manifold pressure controlled
  1. Abbreviation for Multi-point fuel injection
  2. Abbreviation for Multi-Port Fuel Injection
Abbreviation for Miles per gallon, as a measure of fuel consumption. The U.S. gallon is 3.785 litres. The Imperial gallon is 20% larger (4.546 litres). When a vehicle gets 30 mpg (US), he will get 36 mpg (Imperial). The metric system calculates fuel consumption as the number of litres per 100 kilometres. The same vehicle will be giving 7.8 l/100 km.

MPG shortfall
The difference between actual on-road MPG and EPA laboratory test MPG. MPG shortfall is expressed as gallons per mile ratio (GPMR).
Abbreviation for miles per hour. The metric equivalent is Kilometres per hour (kph). To convert Miles to Kilometres, multiply by 1.609344. It may be easier to divide the miles by 10 (i.e., knock off a zero) and then double it four times. Thus 60 mph divided by 10 is 6. Doubled is 12, doubled is 24, doubled is 48, doubled is 96. The accurate figure is 96.56, but 96 is probably close enough. To convert from Kilometres to Miles, divide by 1.609344. It may be easier to multiply is by 10, then chop it in half four times. Thus 70 kilometres becomes 700. Chopped in half it is 350, chopped again is 175, again is 87, and one more time is 43.5. Accurately it is 43.49.
  1. Abbreviation for Multi-point injection
  2. Abbreviation for Multi Port Injection
Abbreviation for Maximum power point tracker
Abbreviation for motor position sensor
Abbreviation for Multi-Purpose Vehicles (like Ford Villager and Windstar, and Daimler-Chrysler Voyager).
Toyota MR2Click image for books on
Toyota MR2
  1. A model of automobile manufactured by Toyota
M road
  1. Road designation used in Britain
    • They are like North-American freeways
    • They are called motorways
    • They have controlled access
    • They have three or four lanes for traffic
Abbreviation for Manufacturing Resource Planning.
Abbreviation for Military Standards. The overriding characteristic of MS fasteners compared to commercial products is the extensive inspection and lot traceability for MS, guaranteeing the chemical, physical and dimensional qualities. While commercial fasteners may look similar and happen to pass many tests given MS products, the commercial fasteners lack the pedigree of guaranteed quality for chemical, physical and dimensional aspects that users who order MS fasteners rely on.
Abbreviation for Material safety data sheet – a document that provides pertinent information and a profile of a particular hazardous substance or mixture. An MSDS is normally developed by the manufacturer or formulator of the hazardous substance or mixture. The MSDS is required to be made available to employees and operators whenever there is the likelihood of the hazardous substance or mixture being introduced into the workplace. Some manufacturers prepare MSDS for products that are NOT considered to be hazardous to show that the product or substance is NOT hazardous.
Abbreviation for Miles Since First Fail
Abbreviation for Miles Since Last Fail
MS oil
Motor Severe oil used in engines that operate under heavy loads and at high speeds. MS oil is required for automotive engines.
Abbreviation for Manufacturers Suggested Retail Price.
Mss point
(minimum stable signal) Best superheat setting which will provide constant or little temperature change at the thermostatic expansion valve temperature sensing element while the system is running.
Abbreviation for Manifold Surface Temperature
Abbreviation for Major Streets Transportation Improvement Program. A serial levy approved by Washington County voters in 1986, 1989 and 1995 to pay for much-needed capital improvements to the transportation system. In 1997, the voters approved Measure 50 making the MSTIP levy part of the county’s permanent property tax rate, but at a reduced level.
  1. Abbreviation for Metric ton (2,250 lbs.).
  2. Abbreviation for Manual Transmission
Abbreviation for mountain bike
Abbreviation for methyl tertiary butyl ether (CH3)3COCH3: An ether intended for gasoline blending as described in Oxygenates.
MTBE Plants
Abbreviation for Metro Transportation Improvement Program. Every two years Metro allocates federal funds through a competitive project ranking process to jurisdictions within the Portland metropolitan area. The primary policy objective of the MTIP is to fund projects that support development of mixed-use and industrial areas identified in Metro’s Region 2040 Growth Concept. A secondary objective of the MTIP is to help develop a multi-modal transportation network with emphasis on funding bicycle, pedestrian, boulevard, freight, green street demonstration, regional transportation options, transit oriented development and transit projects.
Mean time to repair — The time interval (hours) that may be expected to return failed equipment to proper operation.
Abbreviation for Manifold Tune Valve
Mud and snow
(M+S) A type of tire tread which gives maximum traction in mud and snow.
Mud and snow tire

Mud and snow tireMud and snow tire

(M+S tire) A winter tire with a deep tread and big ribs that reduce contact area on dry roads, but give a good grip on loose surfaces. It tends to fling off packed-in snow as the tire revolves.

Mud flap
A rubber or plastic Shield which is positioned behind a wheel (usually the rear wheels) to prevent mud and small rocks from being thrown up against the body of the vehicle or from being thrown at a following vehicle. Also called splash guard


Curved part over the wheels of a motorcycle to minimize splashing
Mud tires
Bold, open-tread tires optimized for mud with disadvantages on hard roads.
  1. A unit with several chambers and baffles through which the exhaust gases are passed to quiet the sounds of the running engine. The British term is silencer.
  2. A hollow, tubular device used in the discharge line of some systems to muffle the thumping sounds made by the compressor. Sometimes used on the low side too.
Muffler, compressor
Sound absorber chamber in refrigeration system. Used to reduce sound of gas pulsations.
Muffler cut-out
A valve located on the exhaust pipe between the engine and the muffler. When opened it allows exhaust gas to pass directly to the open air and thus bypass the muffler making a great noise and slightly increases power. However it can damage the valves if prolonged.
A natural or artificial layer of plant residue or other materials covering the land surface that conserves moisture, holds soil in place, aids in establishing plant cover, and minimizes temperature fluctuations. Thus it prevents soil on embankments from being washed onto the road surface.
Providing any loose covering for exposed forest soils, such as grass, straw, bark, or wood fibers, to help control erosion and protect exposed soil.
A prototype car, usually built with new mechanicals under an old, cobbled body.


Stationary frame member between two doors.
Mullion heater
Electrical heating element mounted in the mullion. Used to keep mullion from sweating or frosting.
A combined fuel injection and ignition system
Multec system
A combined fuel injection and ignition system
Multicon connector system
A 13-pinned electrical connection system for trailers
Multi-cylinder engines
An internal combustion engine having more than one cylinder.
(MF) multiple-focus
Multi-focal headlight
A conventional headlight with a multiple-focus parabolic reflector
Multi-function control stalk
A rod-shaped control mounted on the steering column near the steering wheel. A unit could operate the signal lights, headlight dimmer switch, wipers, windshield washer, cruise control, and horn
Multigrade oil
An engine oil that meets the viscosity requirements of several different single-grade engine oil types. Also called Multi-viscosity oil
Multigrip pliers
Pliers with an adjustable head allowing different jaw widths
Multi-hole nozzle
A two-hole, three-hole, or four-hole injector nozzle in a direct injection engine.

Multi-inlet pump
Multileaf spring
A Leaf spring with several flat leaves bundled together by steel bands.
Multi-link independent rear suspension
A special multi-link rear suspension design, developed by Mercedes-Benz for the W 201 series
Multi-link rear suspension
A general term for independent rear suspension layouts incorporating several control arms.

Multilink suspension
A Rear suspension consisting of at least four links, or arms, and no Struts. Because multilink suspensions assign specific wheel-locating duties to each element, they provide great flexibility for optimizing both ride and handling.
An electrical test meter that can be used to test for voltage, current, or resistance.

See Intermodal Transportation.
Multi-piece rim
A rim type incorporating at least one demountable bead seat and/or rim flange to allow tire mounting. The opposite is a One-piece rim. The bead seats of all multi-piece rims (except flat base rims) have a 5° taper; rims incorporating the semi-drop center, the tapered bead seat or the flat base design are multi-piece rims
Multi-piece wheel
A wheel type incorporating at least one demountable bead seat and/or rim flange to allow tire mounting. The opposite is a One-piece wheel. The bead seats of all multi-piece wheels (except flat base rims) have a 5° taper; wheels incorporating the semi-drop center, the tapered bead seat or the flat base design are multi-piece rims
Multi-plate clutch
A clutch assembly using more than one driving plate and more than one driven plate. British term for Multiple-disc clutch
Multiplate clutch
A clutch with several friction and drive plates. Its compact size makes it ideal for motorcycles
Multiple disc
Multiple disc clutch
A clutch which has several clutch discs in its construction. The greater number of discs allows the size of the Bell housing to be smaller in diameter and still maintain efficiency. A clutch with more than one driven plate, usually of the oil-immersed type; frequently used in motorcycle drive trains, in automatic transmissions of cars, in power distribution systems of 4WD vehicles, and as locking elements in limited-slip differentials.

Multiple-disc limited-slip differential
Limited-slip differential incorporating multiple discs as locking or slip-inhibiting devices
Multiple-plate clutch
British term for Multiple-disc clutch
Multiple-point injection
Multiple ports
Use of many small transfer ports rather than two large ports in a two-stroke cycle cylinder. This provides improved scavenging.
Multiple-spark coil
Multiple-spark ignition coil
Multiple stage compressor
Compressor having two or more compressive steps. Discharge from each step is the intake pressure of the next in series.
Multiple Strand Chain
A Roller Chain (or other chain) made up of two or more strands assembled as a single structure on pins extending through the entire assembly.
Multiple Strand Factor
A factor by which the horsepower rating of a single-strand chain is multiplied to obtain the horsepower capacity of a chain with two or more strands.
Multiple system
Refrigerating mechanism in which several evaporators are connected to one condensing unit.
Multiple-use path
(MUP) A pathway dedicated for pedestrians and bicycles, but not other vehicles.
Multiplex technology
In cars, connecting lamps, wipers, horn, etc. to a single power cable via electronically controlled modules, making it easier to diagnose faults and to service the problem
Multiplier vacuum booster
A vacuum brake power booster that installs between the master cylinder and the wheel friction assemblies. Actuated by hydraulic pressure from the master cylinder.
Multi-point fuel injection
(MPFI) a fuel injection system that uses one injector per cylinder, mounted on the engine to spray fuel near the intake valve are or the combustion chamber. Also called Multi-port injection
Multi-point injection
(MPI) Gasoline fuel-injection system in which only air enters the inlet manifold; as the air approaches the inlet valve, an injection valve opens in the valve port, spraying fuel into the airstream.


Multi-port injection
A fuel injection system that uses one injector per cylinder, mounted on the engine to spray fuel near the intake valve are or the combustion chamber. Also called Multi-point fuel injection
Multi-port injection
A fuel injection system that uses one injector per cylinder, mounted on the engine to spray fuel near the intake valve are or the combustion chamber. Also called Multi-point fuel injection
Multi-powered Electric Vehicle
A vehicle with two or more power sources for propelling it, sometimes known as a hybrid vehicle.
Multi-purpose file
A flat file with faces featuring different cuts, e.g., coarse cut on one side and smooth cut on the other
Multipurpose ship
A ship designed for carrying different types of cargoes requiring different methods of handling.


Multi-purpose tire
A tire that is a combination or compromise between on-road and mud tires.
Multi-reed cage
A reed valve in a two-stroke induction control which consists of several petals
Multi-spark coil
A type of ignition coil used in static high-voltage distribution, designed as a double-spark or four-spark coil
Multi-spark ignition coil
A type of ignition coil used in static high-voltage distribution, designed as a double-spark or four-spark coil
Multi-stage pump
A pump with two or more stages (impellers/diffusers or other pumping elements) operating in series. Multi-stage centrifugal pumps are employed to operate against higher pressures, where several impellers are built onto one shaft in the same casing
Multi-storey car park
A car park with many levels
Multi-suction pump
A centrifugal pump with several impellers connected in parallel; i.e., the flow is separated into two or more partial flows. Multi-suction usually means double suction in practice
Multi-viscosity oil
Oil meeting SAE Requirements for both low temperature requirements of a light oil and the high temperature requirements of a heavy oil. Example (SAE 10W-30). Also called Multiweight.
Multi-viscosity oils
Oils meeting SAE Requirements for both low temperature requirements of a light oil and the high temperature requirements of a heavy oil. Example (SAE 10W-30). Also called Multiweight.
Multi-weight oil
An oil that flows like a thin oil when cold, but lubricates like a thick oil when hot. For example, 10W-40 at 0°F (-18°C) flows like a 10W oil; at 210°F (100°C) it flows like a 40W oil.
A vehicle brand of which the 1950-54 Jet models are milestone cars.
Abbreviation for Multiple-use path where pedestrians and bicycles share the pathway, but cars and motorcycles are forbidden.
A customized designed air-brushed paintwork on the side panels of vans, cars, and motorcycles
Muscle car
  1. A two-door car (including hardtop or convertible) built during 1961-1973 usually with a powerful engine. Includes Ford Mustang, Cobra, and Cougars, etc.; General motors GTO, Grand Prix, Camaro, and Firebird, etc.; Chrysler Charger, GTX, and Satellite, etc. It must be in original form with no modern technology, equipment, or refinements except wheels.
  2. An automobile with a high horsepower engine, modest weight, and capable of producing high levels of acceleration. The term principally refers to American, Australian or South African models and generally describes a 2-door rear wheel drive mid-size car with special trim. Commonly found with a large, powerful V8 engine intended for maximum torque on the street or in drag racing competitions. Other factors used in defining this category of car are their age and country of origin. A classic muscle car is usually made in the U.S. or Australia between 1964 and 1975. The term ‘muscle car’ did not enter common usage until after production of the cars had essentially ended. It is generally accepted that popular, widespread usage of the term took hold by the early to mid-1980s. During their heyday, print media usually referred to this class of vehicle as ‘Supercars’.
When a design mimics human and animal forms. The designs surfaces are handled in a way that has muscle-like definition.
Mush pot
A container used to keep body lead bars in a semi-liquid state to enable them to be spread directly onto the car body
Mushroom-shaped dolly
A dolly with a shank to allow it to be hand-held or clamped in a vice; a more or less rounded head may be fitted to one or both ends of the shank
Mushroom tappet
A tappet shaped like a mushroom located on the underside of a pushrod operating the valves of a four-stroke engine.

Mushroom valve
A type of bog that has developed over thousands of years in depressions, on flat areas, and on gentle to steep slopes. These bogs have poorly drained, acidic, organic soils supporting vegetation that can be (1) predominantly sphagnum moss; (2) herbaceous plants, sedges, and rushes; (3) predominantly sedges and rushes; or (4) a combination of sphagnum moss and herbaceous plants. These bogs may have some shrub and stunted conifers, but not enough to classify them as forested lands.
Ford MustangClick image for books on
Ford Mustang
  1. A Ford vehicle brand of which the 1965-67 GT/GTA V-8 models are milestone cars.
  2. The 1969-70 Boss 302/Mach 1 models are milestone cars
Abbreviation for Manual on Uniform Traffic Control Devices. US Highway Traffic Engineering Terminology. The United States Federal Highway Administration’s Manual On Uniform Traffic Control Devices offers guidance on all aspects of road signs, traffic lights and similar matters. Although the MUTCD is intended as a national standard, most states publish a supplement listing their own variations. This abbreviation is not used on road signs, nor is it likely to be understood by the general public. However, it is very frequently used in relevant documents available on the Internet.
Mutual inductance
A condition that takes place when the current in one winding induces an EMF in another winding in the same magnetic circuit
Motor Vessel or Diesel Engine driven ship
Abbreviation for Manual valve
Abbreviation for Medium Van (e.g., Toyota Hiace).
Abbreviation for Manual Valve Lever Position
Abbreviation for Motor Vehicle Manufacturers Association.
Abbreviation for Manifold vacuum sensor
Abbreviation for Motor Vehicle Safety Act.
Abbreviation for Motor Vehicle Traffic Accidents
Abbreviation for Manifold Vacuum Zone


Abbreviation for Motocross


Abbreviation for Model year