Glossary of Automotive Terms – E

Letter E – Dictionary of Automotive Terms

Abbreviation for Economy Gear
(Gasohol) Ethanol/gasoline mixture containing 10% denatured ethanol and 90% gasoline, by volume.
Abbreviation for Electronic 4-Speed Overdrive
A fuel containing a mixture of 85 percent ethanol and 15 percent gasoline
A fuel mixture containing 93% ethanol, 5% methanol and 2% Kerosene, by volume.
A fuel containing a mixture of 95 percent ethanol and 5 percent gasoline
Abbreviation for Electronic Air Control — replaced by AIR
Abbreviation for Electronic air control valve. A valve used in fuel-injection system, usually computer controlled, that controls the amount of air bypassing the throttle during idle. The more air that bypasses the throttle, the higher the idle speed
EAC Valve
An abbreviation for Electric air control valve. This is the GM version of a diverter air gulp valve, providing three functions in a single valve

  • the normal diverter valve function, i.e., it diverts air on rapid increase in manifold vacuum;
  • it relieves pressure by diverting air to the air cleaner when the air injection system pressure exceeds a certain set level;
  • being solenoid-controlled, it allows air to be diverted under any desired operating mode


EagleClick image for books on

A brand of automobile which was a carry-over from the AMC Eagle and later produced by Chrysler. It included the following models:

  • Wagon (1988)
  • Medallion (1988-1989)
  • Premier (1988-1992)
  • Vista (1988-1992)
  • Summit (1989-1996)
  • Talon (1990-1998)
  • 2000GTX (1991-1992)
  • Vision (1993-1997)
Abbreviation for Electronic Secondary Air Injection
Abbreviation for Egyptian Automobile Manufacturers Association.
A projection in the shape of an ear, usually as a lug or support for other components such as the brackets which are part of the fork cover and to which the headlight is mounted on a motorcycle. It is also a spoiler behind the rear windows to improve stability in side winds.


Abbreviation for estimated additional resources
Earles forks
Long leading-link motorcycle forks, i.e., front suspension has a pivoting fork controlled by twin shock absorbers. Designed by Ernie Earles, they were used by many manufactures of motorcycles in the 1950s
Early Fuel Evaporation
Used only on carburetor-equipped engines, a system where heat is used to help increase early fuel evaporation of the cold-start air/fuel mixture to achieve more efficient combustion and lower emissions. GM used an electric grid system.
Early fuel evaporation system
(EFE) A system that heats the inlet manifold to provide a warm air/fuel mixture, reducing condensation and improving fuel evaporation, thus improving cold engine operation and reducing exhaust emissions. An EFE system operated by engine exhaust gas responds quicker to engine heat-up than systems heated by engine coolant; some EFE systems use an electric heater in the intake duct
Early termination
A vehicle’s depreciation is highest in the first few months after it leaves the dealer’s lot. Since a lessee pays for depreciation in equal monthly payments, lessees who end a lease early have almost always used up more of a car’s value than they’ve paid for. Therefore, lease contracts generally include penalties for early termination. Be aware of these penalties before you sign the lease contract and consider your ability to fulfill the contract.
Ears on
Trucker slang for CB is turned on as in ‘Any smokeys out there with their ears on?’
British term for ground
Earth connection
British term for ground connection
Earth electrode
British term for ground electrode


Earth return
British term for Ground return
Earth strap
British term for Ground strap
Earth wire
British term for Ground wire.
Excavating, ditching, trenching, backfilling, embankment construction, grading, leveling, borrow, and other earth-moving work required in the construction of the project.
Abbreviation for Electronic air suspension. Introduced in the 1993 model year on certain Range Rover models further to enhance standards of road noise insulation, ride and handling, the system substitutes air bags and a live-line pneumatic system, (i.e., an electrically driven compressor, air pressure reservoir and associated controls) for the steel coil springs used on the rest of the Land Rover model range. Logic- controlled by an electronic control unit, height sensors and driver controls, the system maintains front and rear self-leveling in the five height modes listed below. These notes show the versatility of the system and the purpose for which it was designed. However, for the casual driver, new to the vehicle, no prior knowledge or expertise is required; FAS will cycle automatically through appropriate modes according to prior programming. The driver need not even know EAS is fitted. On engine start-up EAS assumes the last selected ride height.
Allows another person the right to use private land for a specific purpose. The most usual easements are those granted to public utility companies to run lines on or under private property. Other common easements are for storm drainage pipes and ditches, for walkways, and for access roads.
Ease up on the accelerator
The action of releasing the accelerator partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of Depress the accelerator or Step on the accelerator.
Ease up on the gas pedal
The action of releasing the gas pedal partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of Depress the gas pedal or Step on the gas pedal..
Ease up on the throttle
The action of releasing the twist-grip or throttle lever partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of Engaging the throttle or Cranking on the throttle..
Ease up on the throttle pedal
The action of releasing the throttle pedal partially or completely in order to reduce the amount of fuel entering the engine and thus slow down the speed of the vehicle. Opposite of Depress the throttle pedal or Step on the throttle pedal..
Easing fluid
Penetrating oil
Eastern hand truck
A device used to transport goods manually with wheels outside the side rails. Compare Western hand truck
American developer of high quality aluminum and carbon fiber bicycle products.
East-west layout
Transverse positioning of the engine across the car from left to right, found in many front-wheel drive designs. Also called Transverse engine. The opposite is North-south layout.
EAS Valve
The valve in an emission control system governing the airflow from the air pump in connection with the EAC valve. When its solenoid is energized, air is directed into the exhaust ports to increase oxidation and accelerate catalytic converter heat-up to operating temperature, and when its solenoid is de-energized, it switches airflow between the converter beds to help the oxidizing catalyst to decrease the CO and HC levels
Easy access cab

Easy access cabEasy access cab

A regular cab pickup with an extra fold-out section behind the door to allow you to have access to the things behind the front seat. Unlike an Extended cab, there is no seating behind the front seat.

Easy out
A brand name for a Screw extractor.
A brand name for a Screw extractor.
To corrode and remove the metal from a body panel which has been subject to excessive rust
Eat away
The effect of excessive rust which has seriously corroded a body panel so that there is almost no original metal left
Trucker slang for Truck stop Cafe as in ‘It’s been so long since I stopped at the eat-em-up that my stomach thinks my throat’s been slashed.’
Abbreviation for Electronic Brake Control Module
Abbreviation for Electronic brake distribution — a system that helps reduce stopping distances by re-proportioning the braking force from rear to front as the vehicle stops and its weight shifts forward.
Hard black rubber compound especially one containing no filler
E box
Any electronic box including Capacitive discharge ignition and computer controlled devices.
Any electronic box including Capacitive discharge ignition and computer controlled devices.
Abbreviation for Exhaust Back Pressure
Abbreviation for Electronic Brake T/C Module
Abbreviation for Engine Control
Abbreviation for Electronic control assembly
Abbreviation for Electronic climate control
  1. Two circles, one within the other, neither sharing the same center, i.e., they are off-center.
  2. A protrusion on a shaft that rubs against or is connected to another part, such as a cam on a camshaft.
  3. A part transmitting an eccentric drive, such as a disc with a provision for a drive from its outer part, or an eccentric shaft
  4. Off center. A brake drum defect caused by unequal wear, drum distortion, or both
Eccentric bolt
A bolt with centers of head and body on different axis so that one is off-center in relation to the other.
Eccentric drive
A drive from a point not on the axis of the driving shaft, e.g., from the outer part of a disc, so that a reciprocating or up and down motion is transmitted; used in pumps or for a camshaft drive
Eccentric journals
These are used to attach the connecting rods to the crankshaft (also called metal shafts)
Eccentric rotor pump
Rotor-type pump
Eccentric shaft
A shaft transmitting eccentric motion
Abbreviation for electronic concentrated control system
ECE test cycle
A 13 minute, three-part test of automotive emissions for compliance with emission standards, adopted by most European countries, simulating urban driving conditions, i.e., involving relatively long idling periods and speeds below 35 mph, emission characteristics at cruising speeds not being considered
Echelon parking
A British term for Angle parking
  1. Abbreviation for electronic control injection
  2. Abbreviation for electronically controlled injection
  3. Abbreviation for Extended Compressor at Idle
Abbreviation for electronic control ignition timing
Abbreviation for Engine Coolant Level
A 2+2 Coupe produced by Lotus from 1975 to 1982. This vehicle was the basis for the current Lotus Excel.


A fastener that is secured to grooves in a shaft.

  1. Abbreviation for Electronic Control Module which is the master computer responsible for interpreting electrical signals sent by engine sensors and for activating automated engine components and processes accordingly in order to produce optimum performance.
  2. Abbreviation for Engine Control Module
Ecological damage
Damage to the environment, usually in the form of pollution, such as that caused by vehicle emissions
Ecologically harmful
Damaging to the environment automotive exhaust gases are ecologically harmful
Science of life balance on earth.
The determination of how much money or fuel is required to cover a particular distance. Good economy involves driving at a steady rate, avoiding rapid starts and stops, driving in the highest possible Gear, avoiding using power- robbing components (e.g., air conditioning), proper tire inflation, etc.
Economic Life
The output from a program which identifies the number of trips the pallet will make provided it is properly repaired, which maximizes a return on the investment.
A device for making a vehicle use less fuel, either by regulating the flow of fuel, or by admitting extra air to the air/fuel mixture — especially when cruising
Economizer valve
A fuel flow control device within the carburetor.
The ratio between a product or service and its value.

Economy device
Economy gear
High Gear designed for economical cruising often better than 11 ratio like an overdrive.
Economy jet
An additional jet in a carburetor admitting extra air to the air/fuel mixture — especially when cruising
Economy ratio
An Overdrive Gear ratio better then 11 for economical cruising
  1. Abbreviation for electronically controlled suspension.
  2. Abbreviation for Evaporation control system
  3. Abbreviation for emission control system
  1. Abbreviation for Engine coolant temperature sensor
  2. Abbreviation for electronically controlled transmission
Abbreviation for Electronic Control Unit
Eddy current
An electric current induced within the body of a conductor when that conductor either moves through a nonuniform magnetic field or is in a region where there is a change in magnetic flux.
Eddy currents
  1. Induced currents flowing in a core.
  2. Localized currents induced in an iron core by alternating magnetic flux. These currents translate into losses (heat), and their minimization is an important factor in lamination design
Abbreviation for Electro-Drive Fan
Edge binding
Tape for securing the edges of carpets
A series of codes on the side of a brake lining that identify material, and the friction coefficient of the lining. Only meant for identification and comparison, the edgebrand does not indicate lining quality.
Edge code
A manufacturer’s code used to identify friction materials.
Edge guard
Rubber or plastic, U-section strip fitted to panel edges to protect them against chipping, etc.
Edge Energy
Edge joint
A joint formed when two pieces of metal are lapped with at least one edge of each at an edge of the other.
Edge protection
Protection of edges against corrosion, e.g.. by weatherstrips
The tendency of crankshaft main bearings to ride up the radius (rather than seat on the journal) when the radius is too large
Edge tire
Edge trim
Rubber or plastic, U-section strip fitted to panel edges to protect them against chipping, etc.
A colloquial term used by vehicle salespeople to describe a customer who may or may not be able to get his car financed. He is on the edge of getting financing.
Abbreviation for Electronic Data Interchange — The business-to-business interconnection of computers for the rapid exchange of a wide variety of documents, from bills of lading to build tickets at auto plants.
Abbreviation for Electronic Direct Ignition System — replaced by EI
Edison base
A light bulb base that is threaded.
Edison screw
A light bulb base that is threaded
Abbreviation for Electronic Distributor Modulator (Ford)

Abbreviation for Event Data Recorder — a device which is sometimes called an automobile black box which records fifteen critical functions of the engine and drivetrain.

EdselClick image for books on

A model of automobile manufactured by Ford

Education Foundation
Edwardian car
A car built in Great Britain between 1905 and 1918
  1. Abbreviation for Electronic engine control system
  2. Abbreviation for Evaporative emission control system
Abbreviation for Control of Ignition Timing
Abbreviation for Control of Ignition Timing and Fuel Delivery Through a Feed Carburetor System
Abbreviation for Control of Ignition Timing and Fuel Delivery Through a Central Fuel Injection System
Abbreviation for Control of Ignition Timing and Fuel Delivery Through an Electronic Fuel Injection System
Abbreviation for evaporative emissions control system
Abbreviation for Electronic EGR (Solenoid)
EEGR Monitor
Abbreviation for Electronic EGR Tester
Abbreviation for Electronically Erasable Programmable Read Only Memory
Abbreviation for Energy efficiency ratio
Abbreviation for Evaporative emission shed system
Abbreviation for Evaporator equalized valve in receiver
  1. Abbreviation for electronic fuel control
  2. Abbreviation for Electronic Feedback Carburetor (Chrysler)
Abbreviation for Electronic Fuel Control Assembly (Ford)
Abbreviation for Early fuel evaporation system
EFE system
Abbreviation for Early Fuel Evaporation System
  1. Actual rather than theoretical or potential.
  2. Producing an effect.
Effective area
Actual flow area of an air inlet or outlet. Gross area minus area of vanes or grille bars.
Effective deflection
Deflection of a suspension system under a particular load
Effectiveness Buildup
Effective pedal travel
The portion of brake pedal travel converted to piston movement in the master cylinder.
Effective pressure
Effective stroke
Working or power stroke in a two-stroke engine
Effective temperature
Overall effect on a human of air temperature, humidity, and air movement.
  1. The accomplishment of something with the least amount of effort, energy, or fuel.
  2. Output of a device, system, or activity, divided by the input necessary to create the output. In a compressor the efficiency would be the work output, as measured by pressure change, divided by the energy input (usually electrical).
  3. The efficiency of an electrical motor is the ratio of mechanical output to electrical input. It represents the effectiveness with which the electrical motor converts electrical energy into mechanical energy
  4. A measure (usually a ratio) of the useful energy provided by a dynamic system versus the total energy supplied to it during a specific period of operation.
Efficiency Gas Furnace
Efficiency of a solar cell
The ratio of the electrical power output of a solar cell to the solar power that it intercepts. For example, a solar cell 3 inches (7.6 cm) in diameter intercepts about 2.39 watts of solar power under full sun conditions. If the electrical output of this cell is 0.34 watt, the efficiency will be (0.34/2.39)=0.14, or 14%.
Efficiency Ratio
Efficient Motors
The products of combustion plus the excess air discharged from gas utilization equipment


The force which is doing work on an object.

(EFi) Abbreviation for Electronic Fuel Injection
Abbreviation for Engine Fuel Temperature
Abbreviation for Early Fuel Evaporation
Abbreviation for Exhaust gas check valve
Eggcrate grille?
Eggcrate grille
A radiator grille with crisscrossing bars forming gaps which are more or less square. One of the distinctive characteristics of Cadillac cars
Abbreviation for Electronic gasoline injection
E Glass
Abbreviation for Exhaust gas oxygen sensor. The detection device in the exhaust that measures the lean/rich state of the AFR. Uses a closed loop algorithm to control feedback.
Abbreviation for EGO Signal Return (Ford)
Abbreviation for Exhaust-gas recirculation. Introduces exhaust gas into inlet system to reduce NOx Enhanced. It shows EGRVR percentage engaged.

Abbreviation for EGR Boost Sensor
Abbreviation for EGR control solenoid
Abbreviation for EGR Control Back Pressure Transducer
EGR control solenoid

EGR control solenoidEGR control solenoid

(EGRC) energizes to allow manifold vacuum to the EGR gas temperature.

EGR cooler assembly
Heat exchanger using engine coolant to reduce exhaust gas temperature
EGR function control
A device which controls or modifies EGR valve position
EGR function sensor
A device that identifies if the EGR system is functioning properly
EGR Monitor
Abbreviation for OBDII EGR Test
Abbreviation for EGR Valve Position Sensor (Mazda)
EGR System
Abbreviation for Exhaust Gas Recirculation Temperature — Replacement term for EGTS
Abbreviation for Exhaust Gas Recirculation Thermal Vacuum Valve
  1. Abbreviation for EGR vent solenoid
  2. Abbreviation for Exhaust Gas Recirculation Vent Solenoid
EGR vacuum
A vacuum source above the closed throttle plate; used for control of ported EGR valves. Vacuum is zero at closed throttle
EGR valve
  1. A part of an EGR system mounted on or near the inlet manifold and controlled by inlet manifold vacuum, which is usually closed at idle and low speeds, but opens during acceleration, admitting exhaust gas to the inlet manifold. Most EGR valves are of the single diaphragm type, some are dual diaphragm valves connected to two separate vacuum sources to more closely match EGR function to engine loads; for the same purpose, EGR valves are frequently governed by additional regulating devices.
  2. A valve used to introduce exhaust gases into the intake air stream. There are several types.
EGR valve position sensor
(EVP) A potentiometric detection device used in electronically controlled EGR system. Sensor wiper position is proportional to EGR valve pintle position, which allows electronic control assembly to determine actual EGR flow at any point in time
EGR vent solenoid
(EGRV) electrical solenoid that normally vents EGRC vacuum line. When EGRV is energized, EGRC can open the EGR valve
EGR venturi vacuum amplifier
A device that uses a relatively weak venturi vacuum to control a manifold vacuum signal to operate the EGR valve. Contains a check valve and relief valve that open whenever the venturi vacuum signal is equal to or greater than manifold vacuum
Abbreviation for Exhaust Gas Temperature Switch A term replaced by EGRT
Abbreviation for Electro-Hydraulic
Abbreviation for Electrohydraulic actuator, same as Differential pressure regulator
Abbreviation for Integrated Electronic Ignition System a replacement term for EDIS
  1. Abbreviation for the Energy Information Administration. An independent agency within the U.S. Department of Energy that develops surveys, collects energy data, and analyzes and models energy issues. The Agency must meet the requests of Congress, other elements within the Department of Energy, Federal Energy Regulatory Commission, the Executive Branch, its own independent needs, and assist the general public, or other interest groups, without taking a policy position.
  2. Abbreviation for Electronics Industries Association.
Abbreviation for electronic idle control valve. It changes the amount of air bypassing into the intake manifold in response to electric signals sent to the (ECU) from a number of components
Eight-cylinder engine, or a vehicle fitted with one; the cylinders may be in-line (a straight eight) or in a V-layout (a V-8).

Eighteen wheeler
Colloquial term for a combination vehicle consisting of a three axle tractor pulling a two axle semitrailer or a two axle tractor pulling a three axle semitrailer.
8 trk
Abbreviation for Eight-track tape player found in many ’60s and some ’70s cars.
Abbreviation for Eight-track tape player found in many ’60s and some ’70s cars.
Eight track
An 8-track tape player found in many ’60s and some ’70s cars.
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Oldsmobile 88

A model of automobile produced by Oldsmobile from 1941 to 1999. The 1949-50 88 Coupe, Convertible, and Holiday are milestone cars.

Engine Identification Number
  1. Abbreviation for electronic ignition system which uses a Reluctor and a pick up coil along with a module to replace the ignition points and condenser
  2. Abbreviation for electronic injection system
  3. Abbreviation for Environmental Impact Statement — an analysis of the environmental impacts of proposed land development and transportation projects; conducted for federally funded or approved projects per NEPA. A draft EIS is circulated to the public and agencies with approval authority for comment.
To push or throw out
Eject button
Button on a cassette player or CD player for taking out the cassette or CD
Device which uses high fluid velocity, such as a venturi, to create low pressure or vacuum at its throat to draw in fluid from another source.

Abbreviation for electrical load control unit
A two-seater roadster produced by Lotus from 1964 to 1974.
Elapsed time
(ET) The length of time it takes a Dragster to complete the one-fourth mile run.
  1. The ability to recover the original size and shape after being deformed, especially stretched, forces are released.
  2. The property of an adhesive or sealer which enables it to recover its original shape and size when deforming forces are removed. It is the ability to change size or shape repeatedly without breaking the molecular bonds that cause an object to hold its shape.
Elastic limit
  1. The point beyond which a deformed piece of metal will no longer return to its original shape.
  2. The highest load a part (i.e., chain strand) can sustain without incurring a permanent change in length.
  1. A term which includes natural rubber and the many synthetic materials that possess rubber-like properties.
  2. An elastic macromolecular material that at room temperature returns rapidly to approximately its initial dimensions and shape after substantial deformation by a weak stress and release of the stress.
  3. A classification of rubber-like substances used in the formulation of adhesives, coatings, and sealers without reference to their composition. Also classed as an elastic material that can be stretched repeatedly to at least twice its original length and, upon sudden release of stress, to return with equal force to its approximate original length Thermoplastic elastomers
  4. An elastic Polymer, a springy plastic used commonly as a spring or shock absorber, particularly in suspension forks and similar mechanisms.
Abbreviation for Electronic Lean Burn (Chrysler)
A pipe or rod with a bend, usually at right angles.

Electronic level control
El Camino
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Chevrolet El Camino

A model of vehicle produced by the Chevrolet division of General Motors from 1959-87 as a response to Ford’s Ranchero. It had the front end of a car, but the back end like the open bed of a truck.

A vehicle brand of which the 1925-33 Models: 8-80, 8-81, 8-90, 8-91, 8-92, 120, 130 and 140 are classic cars
Abbreviation for Evaporative Loss Control Device. A filter canister which is controlled by a signal from the ECU, the filter canister traps gaseous hydrocarbons from the fuel tank in its activated charcoal filter for subsequent burning in the engine on purging of the filter. The purging function is dependent on engine load and engine speed.
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Cadillac Eldorado

A Cadillac vehicle brand of which the 1953-58, 67-70 Eldorado models are milestone cars. The 1957-58 Eldorado Brougham models are milestone cars. Also see the history of Cadillac Eldorado. Several Cadillac models used the name:

  • Eldorado (1953-2002)
  • Eldorado Biarritz (1956-64, 1976-91)
  • Eldorado Brougham (1957-60)
  • Eldorado Seville (1956-60)
  • Fleetwood Eldorado (1965-2003)
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Buick Electra

A model of automobile manufactured by Buick Division of General Motors from 1959-90

Operated by or derived from electricity

Electric air control valve
The EAC valve
Electric air switching valve
EAS valve
Relating to electricity

Electrical activation
The process of treating a cathode to increase its rate of reduction.
Electrical arcing
Band of sparks formed when an electrical discharge from a conductor jumps to another conductor
Electrical balance
An atom or an object in which positive and negative charges are equal
Electrical Code
Electrical conductivity
The ability of a material to conduct electricity. The opposite is resistivity or resistance.
Electrical coupling
When two coils are so situated that some of the flux set up by either coil links some of the turns of the other, they are said to be electrically coupled
Electrical current
The net transfer of electric charge per unit time; expressed as amperes.
Electrical diagram
A drawing or chart showing the connections of the various electric components and the color-coding of the wires used to connect them. Often called Wiring diagram

Electrical efficiency
The ratio of useful electrical real power output to the total electrical power input.
Electrically enabled programmable read only memory
A non-volatile memory that can be used to store information permanently. This device can have all or selected parts of its memory erased electrically and reprogrammed.
Electrical Manufacturers Association
Electrical potential
Electrical force which moves, or attempts to move, electrons along a conductor or resistance.
Electrical Power
An electric measurement unit of power called a voltampere is equal to the product of 1 volt and 1 ampere. This is equivalent to 1 watt for a direct current system, and a unit of apparent power is separated into real and reactive power. Real power is the work-producing part of apparent power that measures the rate of supply of energy and is denoted as kilowatts (kW). Reactive power is the portion of apparent power that does no work and is referred to as kilovars; this type of power must be supplied to most types of magnetic equipment, such as motors, and is supplied by generator or by electrostatic equipment. Voltamperes are usually divided by 1,000 and called kilovoltamperes (kVA). Energy is denoted by the product of real power and the length of time used; this product is expressed as kilowatthours.
Electrically programmable read only memory
A non-volatile memory that is used to store information permanently. This device can have its contents changed if the entire contents are first ‘erased’ through exposure to ultraviolet light (providing the device has a means of allowing light to reach the silicon level) used to increase brake application force.
Electrical resistance
The difficulty electrons have moving through a conductor or substance.
Electrical screwdriver
A manual screwdriver with an insulated handle and blade for working on electrical circuits. Compare Electric screwdriver which is a battery powered screwdriver.
Electrical spanner
A British term for an Ignition wrench
Electrical system
The system that generates, stores, and distributes electrical current to Crank the engine for starting and to keep it running by providing high voltage to the spark plugs; and to give power to the lights, the Heater motor, radio, and other accessories. It is made up of the ignition system starter motor, battery Alternator Voltage regulator lights, electrical accessories and all the wiring, switches, and Relays.
Electrical transient
Any voltage or current that deviates from the normal steady-state condition.
Electric Brake
Electric brake system
An electrical or electronic system used to actuate the brakes.
Electric car
A car whose only power source is an electric motor and a number of batteries.
Electric charge
A definite quantity of electricity, which-may be positive, as with protons, or negative, as with electrons.


Electric choke
Chokes can be operated by a bimetal spring heated by a solid-state heating unit or by a nichrom-wire resistor. Both types increase temperature just like a coolant-controlled choke as engine warms up
Electric Circuit
Electric current
The flow of electricity passing through a conductor. The preferred unit of measure is the ampere.
Electric defrosting
Use of electric resistance heating coils to melt ice and frost off evaporators during defrosting.
Electric energy
The ability of an electric current to produce work, heat, light, or other forms of energy. It is measured in kilowatthours.
Electric fuel pump
Electrically powered gasoline or diesel pump which draws fuel from the tank and delivers it to the carburetor or fuel injection system
Electric grid
The electrical system
Electric heating
System in which heat from electrical resistance units is used to heat the building.
Electric hybrid vehicle
An electric vehicle that either

  1. operates solely on electricity, but contains an internal combustion motor that generates additional electricity (series hybrid); or
  2. contains an electric system and an internal combustion system and is capable of operating on either system (parallel hybrid).
Electric insulation
Substance which has almost no free electrons.
Electric current used as a power source. Electricity can be generated from a variety of feedstocks including oil, coal, nuclear, hydro, natural gas, wind, and solar. In electric vehicles, onboard rechargeable batteries power an electric motor.

Electric Load
The amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy-consuming equipment of the consumers.
Electric mirror
An external door mirror which is controlled by an electric motor and operated by a switch inside the car
Electric motor
A device which changes electrical energy into rotational motion. In addition to the starter and windshield wiper motors, which were the first electric motors to be added to the automotive electrical system, modern cars include a large number of small motors for driving such items as the electric windows, aerials, Sunroofs, mirrors and seat adjustment, central locking and power hoods; electric-powered cars use large motors for their drive.

Electric motor vehicle
A motor vehicle powered by an electric motor that draws current from rechargeable storage batteries, fuel cells, photovoltaic arrays, or other sources of electric current.
Electric power
The rate at which electric energy is transferred. Electric power is measured by capacity and is commonly expressed in megawatts (MW).
Electric rectifier
Electrical device for converting ac to DC.
Electric screwdriver
Electric ScrewdriverClick image to supersize
Electric Screwdriver

A battery-powered tool which can accept screwdriver bits. Some models resemble a flashlight while others resemble a pistol. It is similar to an electric drill.

Electric top
A power convertible roof. The British term is power hood
Electric Vehicle
(EV) A vehicle powered by one or more electric motors rather than by an internal combustion engine. The most common source of electricity is chemical storage batteries, but also provided by photovoltaic cells or a fuel cell.
Electric water valve
Solenoid type (electrically operated) valve used to turn water flow on and off.
Electric welding

Electric weldingElectric welding

Welding by using an electric current to melt both metal (work) and welding rod, or electrode

Electric wheelchair
See Power wheelchair
Electric windows
Side windows which are raised and lowered by an electric motor which is operated by a switch. Also called a Power window
Electrified texas gate
Chemical (battery) production of electricity.
Electrochemical corrosion
Corrosion involving at least one electrode reaction
Electrochemical process
The direct process end use in which electricity is used to cause a chemical transformation. Major uses of electrochemical process occur in the aluminum industry in which alumina is reduced to molten aluminum metal and oxygen, and in the alkalies and chlorine industry, in which brine is separated into caustic soda, chlorine, and hydrogen.
Electrophoretic painting


  1. An electric conductor through which an electric current enters or leaves a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.
  2. In a spark plug one electrode (the center electrode) is the center rod passing through the insulator. The side electrode is a rod (usually bent) welded to the shell of the spark plug. The distance between them is the spark gapfor an electric arc to start combustion process in an engine.
  3. In welding it is the metal rod that is used in arc welding. A substance which brings electricity up to the point where the arc is to be formed; in other words it is the material immediately adjacent to the arc proper and the one which carries the current to this point. In electric arc welding the electrode is usually melted and becomes a part of the weld.
Electrode adjusting tool
A British term for a spark plug gap gauge
Electrode assembly
The portion of an automatic ignition system containing the electrode(s) and associated insulators, wire lead terminals, spark gap adjustment means and mounting brackets.

Electrode gap
Spark plug gap
A generic term for electrolytic processes in which a metal is deposited at the cathode from a solution of its ions, such as electroplating, or in which paint is deposited in an immersion process by means of electric current
Electrodeposition process
Process in which metallic particles are applied to another metal surface through the use of an electric current.
Electrode spark plug
An electroplating coating of zinc on metal that will rust (i.e., iron or steel).
Electrohydraulic actuator
(EHA) An electronically controlled valve which regulates the fuel flow to the lower chamber of the CIS fuel distributor
Electro-hydraulic booster
A power booster that uses an electric motor and pump to create hydraulic pressure which is then used to increase brake application force.
Electro-hydraulic pump
An electrically powered hydraulic pump used to create pressure in certain portions of the brake system. Typically found in GM Powermaster brake boosters and in ABS hydraulic control units
  1. A method by which chemical reactions are carried out by passage of electric current through a solution of an electrolyte or through a molten salt.
  2. Movement of electricity through a substance which causes a chemical change in the substance or its container.
  1. A non-metallic electrical conductor in which current is carried by the movement of ions.
  2. In automotive batteries, it is a sulfuric acid and water solution. It can be any solution (usually an acid) that will conduct electric current. The acid reacts with the battery plates (usually made of Lead) to produce Direct current electricity.
Relating to electrolysis or an electrolyte
Electrolytic cell
A cell consisting of electrodes immersed in an electrolyte solution for carrying out electrolysis
Electrolytic condenser-capacitor
Plate or surface capable of storing small electrical charges.
Electrolytic corrosion
Electrochemical corrosion causing the electrolytic removal of metal
Electrolytic deposition
Electrolytic galvanizing
Electrolytic process
A process that causes the decomposition of a chemical compound by the use of electricity.
Electrolytic protection
Cathodic protection
A magnet produced by placing a coil of wire around a steel or iron bar. When current flows through the coil the bar becomes magnetized and will remain so as long as the current continues to flow.
Electromagnet alternator
An alternator which uses electromagnets to produce a magnetic field.
Magnetic (Generator) production of electricity.
Electromagnetic brake
A brake that is activated by the action of a solenoid which forces a friction disc against a moving component to slow it or bring it to a stop.
Electromagnetic clutch
Any clutch in which a magnetic force is used to hold the drive in engagement, such as that in the compressor drive of an air-conditioning system
Electromagnetic energy
Energy which has both electrical and magnetic characteristics. Solar energy is electromagnetic.
Electromagnetic induction
Voltage is induced in a coil of wire by moving coil through a magnetic field or by keeping coil stationary and moving magnetic field.
Electromagnetic pickup
Electromagnetic Retarder
An axle-mounted electromagnetic device which helps to slow down a vehicle.


The magnetic field around a conductor when a current is flowing through the conductor.
Any device which uses electrical energy to produce mechanical movement
Electro-Motive Diesel


Electromotive force

  • Force that causes electricity to flow because of a difference in potential between two points.
  • A source of electrical energy required to produce an electric current, produced by devices such as batteries or generators and measured in volts.


Electromotive force voltage
(emf) Electrical force which causes current (free electrons) to flow or move in an electrical circuit. Unit of measurement is the volt.
A negatively charged particle that makes up part of the atom

Electron flow
A current produced by the motion of free electrons towards a positive terminal, whose direction is the opposite to that of the current
Featuring semiconductors (usually transistors) as an operating medium.

Electronic advance
Ignition advance controlled by a computer or other solid state controller.
Electronic air control valve
(EACV) A valve used in fuel-injection system, usually computer controlled, that controls the amount of air bypassing the throttle during idle. The more air that bypasses the throttle, the higher the idle speed
Electronically controlled
Most items can be controlled by a mechanical means (squeeze a lever to move something) or by hydraulics (a lever pushes fluid which applies movement to something) or electronically (move a switch and a servo motor moves something)
Electronically controlled transmission
A transmission that relies on sensors, an Electronic control unit (ECU), and solenoids to control torque convertor lockup and shift points
Electronically-controlled wastegate
A turbo-charger wastegate that is activated by an electric signal from a computer
Electronic brake control module
(EBCM) GM’s term for the Electronic control unit
Electronic brake distribution
(EBD) A system that helps reduce stopping distances by re-proportioning the braking force from rear to front as the vehicle stops and its weight shifts forward.
Electronic brake system
An electrical or electronic system used to actuate the brakes.
Electronic climate control
(ECC) An air conditioning system control which determines and maintains the preset temperature in the passenger compartment.
Electronic cluster
A display showing various functions, including speedometer, tachometer, gauges, etc., using LEDs or LCD technology displaying symbols and bar graphs instead of numbers. The opposite is an analog cluster
Electronic control Assembly
ECA A Ford vehicle computer consisting of a calibration assembly containing the computer memory, its control program, and processor assembly (the computer hardware)
Electronic control diagnostics
Trouble codes which may be referenced on an automatic climate control system to diagnose problems.
Electronic control module

  1. The master computer responsible for interpreting electrical signals sent by engine sensors and for activating automated engine components and processes accordingly in order to produce optimum performance.
  2. A microprocessor that determines the beginning and end of each injection cycle on every cylinder. The ECM determines both fuel metering and injection timing in response to such parameters as engine crankshaft position and rpm, engine coolant and intake air temperature, and absolute intake air boost pressure.
  3. A GM term and also a generic term referring to the computer. The ECM is the brain of the engine control system receiving information from various sensors in the engine compartment. The ECM calculates what is required for proper engine operation and controls the different actuators to achieve it. Also called Electronic control unit
Electronic control unit

  1. A microprocessor and memory with electronic maps, forming the central part of an engine management system or of subsystems such as a fuel injection or ignition system.
  2. The brain of an ABS system. The ECU reads impulses from the wheel speed sensors to determine if anti-lock braking needs to take place. If so, the ECU controls the cycling of the solenoid valves in the hydraulic control unit. Also called Electronic Control Module
Electronic Data Interchange

  • The business-to-business interconnection of computers for the rapid exchange of a wide variety of documents, from bills of lading to build tickets at auto plants.
  • Computer-to-computer communication between two or more companies that is used to generate documents such as purchase orders and invoices. EDI also enables firms to access the information systems of suppliers, customers and carriers to determine real-time status of shipments and inventory.
Electronic EGR valve
The EGR valve used in engine management system in which the EGR flow is controlled by the computer (usually by means of an EGR valve position sensor attached to the EGR valve). Operating vacuum is supplied by EGR solenoid valve(s)
Electronic engine control

  1. The engine management system which controls the ignition system and various other systems, including the exhaust gas recirculation and air-injection systems.
  2. Ford’s computerized engine control system. There are four versions
    1. EEC-I controls engine timing.
    2. EEC-II controls engine timing and fuel (on engines with an FBC system).
    3. EEC-III-FBC is a refined version of EEC-II. EEC-III-CFI controls engine timing and fuel (on engine with an EFI system).
    4. EEC-IV is a refined version of the EEC-III system
Electronic fuel injection
(EFI or EFi) A system that injects fuel into the engine and includes an Electronic control unit to time and meter the flow. Fuel is delivered in intermittent pulses by the opening and closing of solenoid-controlled injectors. Also called Pulsed injection

Electronic gasoline injection
(EGI) Mazda’s fuel injection system for the RX-7, RX-7 Turbo, 323, and 626
Electronic ignition
Electronic ignition system
Electronic Ignition SystemClick image to supersize
Electronic Ignition System

An ignition system using electronic switching devices to assist or eliminate the mechanical breaker points. There are three basic electronic ignitions

  1. contact controlled (the breaker points are retained but merely serve to trigger a transistor which switches the heavy primary current)
  2. magnetically controlled (transistors are used as the switching device for the primary current and the points are eliminated — also called contactless or all-electronic)
  3. capacitor controlled (also called capacitive-discharge system and can be either all-electronic or breaker-point controlled).
Electronic leak detector
Electronic instrument which measures electronic flow across gas gap. Electronic flow changes indicate presence of refrigerant gas molecules.
Electronic navigator
A trip computer which gives estimated time of arrival (ETA), amount of fuel left, average fuel consumption, etc.
Electronic regulator
A solid state device which controls charging system output.
Electronic relay
Electronic switch, such as a triac, which controls a power consuming device.
Electronic ride control
A suspension control system made up of a microprocessor-controlled, electronically adjustable air shock absorbers for automatic selection of the optimum damping characteristics depending on road surface and load conditions
Field of science dealing with electron devices and their uses.

Electronic sensing device
An electronic measuring device for vehicles with fuel injection. It detects changes in speed and driving conditions and determines the amount of fuel to be injected into the combustion chamber thus eliminating the need for carburetors.
Electronic sight glass
Device that sends an audible signal when system is low in refrigerant.
Electronic spark
Electronic spark advance
(ESA) the part of an ECU that controls ignition timing and dwell angle
Electronic spark control
(ESC) The timing of the ignition by means of an ignition map, either integrated into the mapped ignition systems or available as a separate module to enhance transistorized ignition systems. Also called electronic spark timing.
Electronic spark timing
(EST) The timing of the ignition by means of an ignition map, either integrated into the mapped ignition systems or available as a separate module to enhance transistorized ignition systems. Also called electronic spark control.

Electronic spark timing system
(EST) An ECM-controlled timing of ignition spark. This replaces the vacuum or centrifugal mechanism in the distributor and uses the computer to advance or retard the spark timing
Electronic Stability Control
(ESC) When a vehicle strays from the intended travel path or begins to spin out, the ESC automatically brakes individual wheels or reduces throttle to keep the vehicle under control. The system was first introduced by Mercedes Benz in 1994. Although it has been phased in on a number of vehicles (particularly cars and SUVs), it is required on all vehicles in Canada, USA, Australia, and Europe beginning in 2012.
Electronic thermistor
Electrical device that senses temperature change to control an output source

Electronic thermostat
Thermostat that uses electronic components to accomplish various sensing, switching, timing, staging, and display functions.
Electronic traction control
(ETC) A system for reducing wheelspin, incorporating wheel sensors. A standard or optional feature, available only on ABS-equipped vehicles. It inhibits wheel-spin by applying the brake to a spinning rear wheel and thus enhances traction on ice, snow, or in severe off-road conditions. It uses ABS sensors for wheel speed determination and brakes the spinning wheel (through the axle differential) to apply torque to the stationary wheel. Like ABS, it is especially effective in maintaining control when one side of the vehicle is on a more slippery surface than the other — a so-called ‘split-μ surface.’ An instrument panel light illuminates when the system is operating. The function is inhibited above 50 kph, a speed above which unintentional wheel spin is unlikely to occur.
Electronic transmission
A system of controlling the shifting of gears in the transmission by means of electrical pulses sent to solenoids and relays. In mechanical transmissions, the operator moves levers which makes the transmission shift gears.
Electronic transmission control
A system or module for controlling an automatic transmission
Electronic Trip Recorder
A device for recording data on a vehicle’s performance, originally designed for monitoring and optimizing engine performance, in recent years GPS systems have been added to enable dispatchers to geo-locate their trucks and many trip recorders maintain HOS data, eliminating the need for driver maintained logbooks.
Electronic voltage regulator
(EVR) a type of regulator that uses all solid state devices to perform the regulatory functions
Electron theory
The accepted theory of electronics that states that electricity flows from positive to negative.
Electrosomotic drag
The flux of a polar species (H2O) due to its attraction to a proton (H+) that is transported from the anode to the cathode.
Electrophoretic painting.

Electropaint tank
A tank in which items are immersed for electrophoretic paint application
Electrophoretic painting
A process used to apply the first coat of paint (Primer) to car bodies. The process involves using negatively charged paint particles (anodic electropainting) or positively charged paint particles (cathodic electropainting). The cleaned metal parts to be coated are immersed in a tank of electrodeposition paint, and the current is turned on, so that the paint particles are attracted by the positively charged paint particles
Electrophoretic primer
Paint used to prime car bodies by the electrophoretic process
Electro picker
A device which is electrically operated and is used to open locked car doors. It is available only to automotive locksmiths and the police. It consists basically of a vibrator with an attached steel blade. When the vibrating blade is inserted into a lock, it finds its way past the locating pins which would normally block anything but the original key
The process of depositing gold, silver, chrome, nickel, etc., upon an object by placing the object in a special solution and then passing an electric current through the solution. The object forms one terminal, a special electrode the other. Direct current is used.
The process of electrodeposition of metal or alloys from suitable electrolyte solutions. The articles to be plated are connected to the cathode in an electrolyte solution, and direct current is introduced through the anode of the metal to be deposited.

Electrostatic filter
For cleaning air, a type of filter which gives dust particles an electric charge. This causes particles to be attracted to a plate so they can be removed from air.
Electrostatic painting
A painting method using the particle-attracting property of electrostatic charges, in which a direct current of approximately 100,000 volts is applied to a grid of wires through which the paint is sprayed to charge each particle, and the metal objects to be sprayed are connected to the opposite terminal of the high-voltage circuit, so as to attract the paint particles. Also called Electrostatic Spraying
Electrostatic powder coating
(EPC) A painting process in which the outer parts of the body shell are coated with a powder dispersion by means of cathodic immersion, and in which the cavities are coated with cathodic electropaint
Electrostatic spraying
A painting method using the particle-attracting property of electrostatic charges, in which a direct current of approximately 100,000 volts is applied to a grid of wires through which the paint is sprayed to charge each particle, and the metal objects to be sprayed are connected to the opposite terminal of the high-voltage circuit, so as to attract the paint particles. Also called Electrostatic Painting
Electro vacuum relay
(EVR)A combination solenoid vacuum valve and electrical relay which locks out blower operation and closes the fresh air door in cold weather, and switches the system to the recirculating air mode during maximum system use
A solenoid valve
A group of plates in a battery. Three elements for a six volt and six elements for the twelve volt battery. The elements are connected in series.

Elemental Carbon
(EC) Inorganic carbon, as opposed to carbon in organic compounds, sometimes used as a surrogate measure for diesel particulate matter, especially in occupational health environments. Elemental carbon usually accounts for 40-60% of the total DPM mass.
Element Control
Element filter
A disposable oil or air filter that uses gauze or paper as filtering material.
As seen in front, rear or side views. A side elevation, for example, is a side view. The plan or top view is not defined as an elevation.

Elevator bolt

Elevator boltElevator bolt

Bolt with a wide, countersunk flat head, a shallow conical bearing surface, and integrally-formed square neck under the head (to prevent movement), and a unified thread pitch. Used in conveyor systems.

Elliot axle
A solid bar front axle on which the ends span or straddle the steering knuckle.

Elliott steering knuckle
Type of axle in which ends of axle beam straddle spindle

Elliot type axle
Ellipsoidal headlight
A headlight with a reflector which is wider than it is high, and not circular; has replaced the parabolic reflector
Elliptical port shape
Rounded port shape designed to prevent a ring from catching in large ports of a two-stroke engine.
  1. The percentage increase in the length of a specimen when stressed to its yield strength.
  2. Stretching a fastener to the point that it breaks. The percent of elongation at rupture (same as measure of ductility) is determined by dividing the total length after stretching to the original length. Elongation decreases as strength and hardness increases.
Abbreviation for End-of-Life Vehicles.
Abbreviation for Engine Modification
Abbreviation for Electromagnetic Brakes
An object which is attached to a vehicle to identify it. In contrast, a decal is as thin as paper while an emblem is like a medallion.

A reduced toughness or ductility in plastic or metal caused by age, temperature, chemicals, or rough use.

Abbreviation for Electro-Motive Diesel formerly the Electro-Motive Division of General Motors — the world’s largest builder of diesel-electric locomotives for all commercial railroad applications. EMD is also a global provider of diesel power engines for marine propulsion, offshore and land based oil well drilling rigs, and stationary power generation. It was developed by GM in the 1930’s and taken over by GE in the 1980’s.
A sudden, unexpected occurrence, such as a breakdown or the failure of some part, which may be dangerous and demands immediate action.
Emergency brake
A braking system which is independent of the main hydraulic system. It can be used to slow or stop the vehicle if the primary brakes fail, or to hold the vehicle stationary though the brake pedal is not depressed. It usually consists of a foot pedal or hand lever that actuates either front or rear brakes mechanically through a series of cables and linkages. It is also called the Parking brake or E-brake.
Emergency flotation pressure
Very low tire pressure (about 60% of normal road pressures) for traveling on soft ground (e.g., loose sand or snow) at very low speeds (e.g., 20 kmh. Low speed is necessary because the low pressure causes the tire’s sidewall to flex excessively. Also called emergency soft.
Emergency inflator
An aerosol can which inflates a punctured tire and injects sealing compound to provide at least a temporary repair
Emergency Order
A shipment request that is placed and shipped immediately, ahead of all other orders. Also called expedited order
Emergency soft
Emergency transmitter
A transmitter no larger than a car radio, fitted inside the vehicle which enables a driver to radio for help from the security of his own car
Emergency valve
A unit under the control of the driver which, when actuated, will activate the emergency brake system

Emergency windshield
A sheet of clear plastic fitted in place of a broken windshield
Emery cloth
A cloth coated in emery crystals like fine sandpaper for use as an abrasive on metals
Abbreviation for electromotive force

Abbreviation for Electromagnetic Interference
An affectionate name for the RollsRoyce radiator mascot, the Spirit of Ecstasy


Click to supersize
Emission Control System

  1. The passing of gases and other toxic substances into the atmosphere.
  2. Anthropogenic releases of gases to the atmosphere. In the context of global climate change, they consist of radiatively important greenhouse gases (e.g., the release of carbon dioxide during fuel combustion).
Emission control:
A system for restricting the amount of noxious emissions. There are two standards for emission controls: level E for Europe and the more stringent level U for the United States.

Emission Control Information
Emission controls
Emission control system
Emission coefficient
A unique value for scaling emissions to activity data in terms of a standard rate of emissions per unit of activity (e.g., pounds of carbon dioxide emitted per Btu of fossil fuel consumed).
Emission levels
Amounts of toxic substances passed into the atmosphere by motor vehicles
Emission limit
Gases and other pollutants as well as noise coming from a vehicle with an internal combustion engine.


Emissions equipment
Government and environment requirement to keep a vehicle’s exhaust emissions to a minimum. Emissions equipment includes catalytic converter, air pump, and oxygen sensor.
Emission Shed System
Emission standards
Specified maximum emission levels permitted from different classes of motor vehicle in different countries
Emission Vehicle
Emission Vehicle Standards
The lead of a transistor shown using an arrow with a head on it.

Emitting Diode
Total employment in each manufacturing facility, including total manufacturing employees, total support staff, and total engineering/R&D staff. Average number of workers employed by an establishment during the year. Production workers relate to the average number actually engaged in the manufacturing process. Administrative and non-manufacturing includes employees at head offices and sales offices.
Employee benefits
The provision of direct (salary, bonuses, etc.) indirect (vacation leave, medical and dental plans, etc.) and deferred employee compensation (pensions, etc.).
A trailer that contains no freight.
  1. Abbreviation for emission maintenance reminder
  2. Abbreviation for Electronic Module Retard
Abbreviation for Engine Management System
The process of making an emulsion
A mixture of two liquids which do not fully mix, such as oil and water, or specifically of gasoline and air in a carburetor before it is discharged and fully atomized. Water-in-oil emulsions have water as the internal phase and oil as the external, while oil-in-water have oil as the internal phase and water as the external.
Emulsion tube
Part of a fixed jet carburetor, in which air is introduced into the mixture through holes to help atomize it and correct excessive richness at higher engine speeds. 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 Main-well tube
Abbreviation for emission maintenance warning
Abbreviation for Generator or Alternator
A microcomputer decision that results in an engine management system being activated and permitted to operate
Enabled Programmable Read Only Memory
Enabling Criteria
Each Monitor in an OBD system is designed to test and monitor the operation of a specific part of the vehicle’s emissions system: (EGR system, oxygen sensor, catalytic converter, etc.). A specific set of ‘conditions’ or ‘driving procedures’ must be met before the computer can command a Monitor to run tests on its related system. These ‘conditions’ are known as ‘Enabling Criteria.’ The requirements and procedures vary for each Monitor. Some Monitors only require the ignition key to be turned ‘On’ for them to run and complete their diagnostic testing. Others may require a set of complex procedures, such as, starting the vehicle when cold, bringing it to operating temperature, and driving the vehicle under specific conditions before the Monitor can run and complete its diagnostic testing.
Type of paint that dries to a smooth, Glossy Finish. It is easier to apply than cellulose. If cellulose is applied over it, the cellulose will lift (i.e., peel off).

EN block


One piece — such as an engine Cylinder block cast in one piece.
Encapsulated winding
An electrical motor that has its windings structured completely coated with an insulating resin (such as epoxy). This construction type is more designed for exposure to severe atmospheric conditions than is the normal varnished windings.
Abbreviation for an electric motor enclosure
A model of automobile manufactured by Buick Division of General Motors from 2008-current
Enclosed Fan-Cooled Enclosure
Enclosed Non-Ventilated Enclosure
(ENCL) The term used to describe the electrical motor housing as one of the following types

  1. Drip-proof enclosure,
  2. Open drip-proof enclosure,
  3. Explosion-proof enclosure,
  4. Fan cooled enclosure,
  5. Nonventilated enclosure,
  6. Open enclosure,
  7. Totally enclosed enclosure
EncoreClick image for books on

An automobile manufactured by AMC

End alignment
End bearing
End bell
End structure of plate of electric motor which usually holds motor bearings.
End bracket
The cover containing a bearing at each end of a generator or alternator. Also called end cover, End shield, end bell, or end cover plate.

End cap
The cap covering the end of a piece of trim or of a barrel fuse
End Construction
A road sign indicating that you have reached the end of road works.
End cover
The cover containing a bearing at each end of a generator or alternator. Also called end bracket or end cover plate
End cover plate
The cover containing a bearing at each end of a generator or alternator. Also called end cover or end bracket
End cutters
British term for Side cutters
End cutting
End cutting pliers
British term for Side cutters

End dump
A term used to describe various dump trucks or trailers that tilt to unload at the rear.
End float


End form
Any type of connector at the end of a hose or pipe.
End Frame
End gap
End gas
The last part of the fuel-air mixture that has been introduced into the cylinder but has not yet been consumed in the normal Flame-front reaction.
End Gasket Kit
End gear
End gears
End hexagon screwdriver
Ending Inventory
Inventory levels at the end of a specified period.
End lease
Endless chain
A roller chain without a master link for connection of ends. All pin links are permanently riveted.
End lift
(Short form for end-over-end). The maneuver of flying unexpectedly over the handlebars, thus being forcibly ejected from the bike as in ‘If you hit that log you’ll go endo.’
End-of-lease purchase price
If there is a purchase option in the lease contract or agreement, this will be the agreed upon price for the purchase of the vehicle at the end of the lease-the stated residual value. This price may also include additional fees.
End-of term interest rate
End-of-the-line terminal
(EOL) A local terminal which handles the pick-up and delivery of the customer’s freight (as opposed to a consolidation center). Also referred to as a satellite terminal or group terminal.
An instrument used to see into the interior of hollow cavities such as box sections
Chemical reaction in which heat is absorbed.
End piece
End Plate
End play
  1. The looseness in bearing clearance in an axial direction.
  2. Slight movement of shaft along its center line.
  3. Amount of lengthwise movement between two parts.
End plug
The caps that fit onto or into the ends of the handlebars
End shield
That part of the electrical motor housing which supports the bearings and acts as a protective guard to the electrical and rotating parts inside the motor. This part is frequently called the end bracket or end bell.
End Shifter
End speed
End stud
Endurance Limit
The maximum stress that a metal will withstand without failure during a specified large number of cycles of stress.
Endurance test
A test of a material or system over a long period to determine when it will fail
Off-road competition against the clock and usually over long distances
Enduro bike
A mountain bicycle for cross-country endurance races; generally lightweight, mid-travel (3 to 4 inches), dual suspension designs to balance performance and long-ride comfort
To activate (a Solenoid, Relay, etc.) by providing sufficient energy
Capacity (actual or potential) for doing work. It is measured in joules or kilowatt-hours.

The ability to absorb impact forces
Energy absorbing bumper
Energy-absorbing bumper
Energy absorbing steering column
A Steering column which collapses when the vehicle is involved in a crash.
Energy audit
Process of accurately determining the current energy consumption for a given area.
Energy battery
Energy coil
Energy conservation
Process, upon reviewing the calculations for determining head loads, of instituting changes that will result in energy savings.
Energy conversion
The changing of one form of energy into another or into work, such as that in the combustion process, the heat of which is used to turn the engine and thus create motion
Energy efficient motors
Virtually interchangeable with standard motors, but differences in construction make them more energy efficient. Are also known as high-efficiency motors and premium motors.
Energy efficiency ratio
(EER) The ratio of the rated cooling capacity in BTU per hour divided by the amount of electrical power used in watts.

Energy ignition
Energy ignition system
Energy ignition system with electronic spark timing
Energy Information Administration
(EIA) An independent agency within the U.S. Department of Energy that develops surveys, collects energy data, and does analytical and modeling analyses of energy issues. The Agency must satisfy the requests of Congress, other elements within the Department of Energy, Federal Energy Regulatory Commission, the Executive Branch, its own independent needs, and assist the general public, or other interest groups, without taking a policy position.
Energy Management
Energy management control system
Controllers used in a system which optimizes total energy usage in a building or residence.
Energy Policy Act of 1992
(EPACT) This U.S. legislation created a new class of power generators, exempt wholesale generators, that are exempt from the provisions of the Public Holding Company Act of 1935 and grants the authority to the Federal Energy Regulatory Commission to order and condition access by eligible parties to the interconnected transmission grid. It deals with alternative transportation fuels. It accelerates the purchase requirements for AFVs by the federal fleet, proposes eliminating the cap on CAFE credits that manufacturers can earn by producing dual- and flexible-fuel vehicles and requires fleets in large urban areas to purchase AFVs. Establishes tax incentives for purchasing AFVs, converting conventional gasoline vehicles to operate on alternative fuels and installing refueling or recharging facilities by the private sector.
Energy Protection Agency
Energy retarder
Energy source
Any substance or natural phenomenon that can be consumed or transformed to supply heat or power. Examples include petroleum, coal, natural gas, nuclear, biomass, electricity, wind, sunlight, geothermal, water movement, and hydrogen in fuel cells.
Energy Systems
Energy utilization index
(EUI) A number which is used to compare energy usages for different areas. It is calculated by dividing the energy consumption (in BTUs) by the square footage of the conditioned area.
  1. To come into contact and be locked together (with another part).
  2. To bring (a part) into contact with another so that it is locked to it
The result of bringing into locking contact (e.g., of the clutch), or selection of a Gear
Engaging the throttle
The action of causing the throttle linkage to move so that more fuel enters the engine to increase the speed of the vehicle.
Click image to supersize engine
  1. A machine for changing one form of energy (such as fuel energy, thermal energy, chemical energy, or electrical energy) into mechanical energy to produce force or motion. The term applies to the primary source of power generation. In Britain there is a desire to make a clear distinction between engine and motor so that motor refers only to electric power units (e.g., starter motor) and engine for gasoline or diesel powered units. However, even in Britain, combustion driven vehicles are called motor cars and motorcycles. In the U.S.A. the term motor can apply to both types.
  2. A mechanical appliance such as a fire engine.
  3. A mechanical tool such as an instrument or machine of war or an instrument of torture
  4. As a verb: to equip with an engine.


Engine accessory
An extra piece of equipment that runs directly off the engine’s power to supply energy or a fluid to another part of the car. Engine accessories include the alternator, power steering pump, air pump, air conditioning compressor, as well as many others.
Engine adapter
A unit that allows a different engine to be installed in a vehicle and still bolt up to the original transmission.
Engine analyzer
An electronic engine testing device which (because of its size) used to be placed in a cabinet or a movable stand. The modern units are often hand-held and are connected to the vehicle’s diagnostic socket (as in the case of the diagnostic read-out box), which provides data on all aspects of the engine’s state of tune
Engine bay
The engine compartment.
Engine block
Engine BlockClick image to supersize
Engine Block

The cylinder block. The place where the cylinders and pistons reside. The block is the strongest part of the engine and withstands tremendous pressures while the engine is operating.

Engine block heater
Engine brake
A system that is independent of the conventional braking systems which assists in the slowing of a vehicle. A driver would normally down-shift to slow his descent down a hill, using engine compression. The engine brake increases the effectiveness of this retarding force. The most common type is called a ‘Jake Brake’ because the predominant manufacturer is Jacobs Vehicle Equipment Co. Other types of retarders include exhaust retarders, transmission-mounted hydraulic retarders and axle-mounted electromagnetic retarders. Also called Energy retarder, or simply Retarder.
Engine braking
Vehicle retardation derived from engaging a low gear and taking your foot off the throttle:.
Engine braking effect
A retarding effect of an engine when the vehicle is in gear with the throttle closed. Also called a jake brake
Engine calibration unit
An electronic component which can be specifically programmed to the design of each car model to control the M/C solenoid. Plugs into the ECM. Also called a PROM.
Engine capacity
The Swept volume of an engine
Engine compartment
The space where the engine is mounted. Also called the engine bay.

Engine control
Engine control module
(ECM) An advanced electronic computer which monitors engine conditions and then controls engine settings to optimize the combustion of the air/fuel mixture.
Engine control system
Engine-control system
A computer that regulates the operation of the engine by monitoring certain engine characteristics (rpm, coolant temperature, Intake airflow, etc.) through a network of Sensors and then controlling key variables (fuel metering, spark timing EGR, etc.) according to pre-programmed schedules.
Engine coolant
Antifreeze liquid used in the engine’s cooling system
Engine coolant temperature sensor

  1. The Thermistor detection device that provides coolant temperature information to the computer. Used to alter spark advance and EGR flow during warm-up or an overheating condition
  2. A detection device which provides an electrical output proportional to the engine coolant temperature.
Engine cover
The panel which conceals the engine in a mid-engine car. Also called access panel.


  • hood (British bonnet) which covers the engine only in a front-mounted engine.
Engine damage
Breakage, deformation, or scoring of the internal parts of an engine due to running at very high rpms for an extended period of time or with insufficient lubrication. A rod could break off and drive a hole into the cases; a valve could break off or imbed itself into the top of a piston; the piston could heat and expand and thus seize against the cylinder walls; or other types of damage could occur.
Engine depression
Low pressure on the engine side of the throttle caused by piston suction in the inlet manifold
Engine de-rating
Reducing the standard horsepower and speed ratings on an engine because of the kind of service it performs. For example, an intermittent rating will be higher than a continuous rating on an engine.
Engine diagnostic connector
The electrical connector for plugging in the engine analyzer, forming an interface between the engine electronic controls and diagnostic unit, and used to read the engine data as well as any fault codes stored in the memory of the engine controller
Engine displacement
  1. To determine, multiply the volume of the space through which the head of the piston moves in the full length of its stroke by the number of cylinders in the engine. The result is given in cubic inches or liters.
  2. Sum of the volumes swept by an engine’s pistons as they travel up and down in their cylinders. Based upon the area of the bore (diameter of cylinder) and the length of the stroke (distance traveled by piston). Expressed in liters or cubic inches.
  3. Formula: ED=(B/2)² x π x S x C, where ED is Engine displacement, B is bore, S is stroke, C is number of cylinders. (The bore is the diameter, so half the bore is the radius which needs to be squared times π to get the area.)
    • For example a 4-cyl. engine has a bore of 84.5mm and a stroke of 88mm. ED=(84.5/2)² x π x 88 x 4 = 197399 cubic millimetres = 1.974 liters which the manufacturer calls a 2-liter engine.
    • Second example: an 8-cyl engine has a bore of 4.082′ and stroke of 4.06′. The ED= (4.082/2)² x π x 4.06 x 8 = 425.06 cubic inches.
    • To convert from cubic inches to liters, multiply by (2.54)3, thus the 425 cubic inches equates to 6.966 liters (advertised as 7 liters).
    • Likewise to convert from liters to cubic inches, divide by (2.54)3, thus the 1.975 engine in the first example works out to 120.46 cubic inches.
The person who operates and ‘runs’ the railroad locomotive.
Engine flywheel
A spinning plate located at the end of the crankshaft that engages the clutch disk, causing the engine and the transmission to turn at the same rate of speed. The flywheel is also designed to dampen engine vibration caused by the firing of pistons.


Engine hoist
Small crane for lifting an engine out of a motor vehicle, formerly incorporating a block and tackle, but now usually hydraulically operated.


Engine identification number
(EIN) A number stamped on the engine which may or may not match the number on the vehicle identification plate. Also called engine number
Engine knock
When the engine is operating, an audible noise may be heard when the fuel in the cylinders is ignited too early and/or spontaneously, resulting in colliding flame fronts and shock waves which cause high thermal and mechanical stress, and can severely damage the engine.
Engine layout
  1. The type of engine, with reference to the arrangement of its cylinders and their number (as in a flat four, V-twin, or straight eight).
  2. The location of the engine in the vehicle (as in a front mount, mid-mount, or rear engine).
  3. The placement of the engine in the engine compartment e.g., a Transverse or In-line engine
Engine Light
Engine management system
(EMS) An electronic engine control system which covers at least the functioning of the fuel injection and ignition, but may also include emission controls and self-diagnostics
Engine map
As an engine speeds up, the timing needs to be advanced. On older vehicles, this is accomplished mechanically with a counterweight advance in the distributor. In modern vehicles, the timing can be advanced progressively by means of a computer chip which is programmed to provide the ideal timing. It also provides other factors in some engines such as the opening and closing of valves, etc.

Engine misfire


Engine modifications
Alterations to the specification of the engine to increase power output, improve economy, reduce emissions, etc.
Engine mount
One of two or more supports that connect the transmission and engine to the vehicle’s chassis. Composed of rubber and steel, the engine mounts absorb the motion (twisting, vibrating, etc.) produced by the operation of the engine and transmission. They also assist in reducing the noise and motion transmitted to the passenger compartment. The most efficient recently developed mounts are hydraulic, in some cases electronically-controlled.
Engine mounting
A flexible support for the engine in which an elastic medium, usually rubber, is interposed between the lugs on the engine and the frame of the vehicle
Engine noise
The amount of noise produced by the engine when it is running. Engine noise is more noticeable with a diesel at lower speeds
Engine number
(EIN) A number stamped on the engine which may or may not match the number on the vehicle identification plate. Also called engine identification number
Engine oil
Oil within the engine used to lubricate the moving components. At one time the oil was a single grade, but modern engines use Multi-viscosity oil.

Engine 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.

Engine oil gallery
A series of passages, usually drilled, through which oil circulates to key sections of the engine and to the crankshaft
Engine oil pan


Engine oil level warning light
A light on the instrument panel which comes on when the oil in the sump falls below a certain level
Engine overhaul
When an old engine burns too much oil and loses power, it is dismantled and restored to the manufacturer’s original tolerances by replacement of worn parts, reboring the cylinders, regrinding the crankshaft, etc.
Engine overheating
A condition that occurs when the coolant in the cooling system is so hot the metals in the engine are at a temperature that may cause damage to them. In addition, the engine runs poorly and usually stalls.


Engine parameters
A term used in the context of emission controls for those engine characteristics sensitive to engine performance, such as power/bhp, general engine performance, and fuel economy
Engine performance tester
An engine analyzer
Engine sequence test
The test which determines how well oil will prevent engine rusting, corrosion, scuffing, wear, and the formation of Sludge and Varnish.
Engine size
The engine displacement or capacity. The total volume within all cylinders of an engine when pistons are at their lowest positions. The engine is usually measured in liters or cubic inches of displacement (CID). Generally, larger engines result in greater engine power, but less fuel efficiency. There are 61.024 cubic inches in a liter.
Engine speed
The number of revolutions per minute (rpm) at which the engine crankshaft turns. The vehicle itself may be stationary or in motion.
Engine speed limiter
A device which acts as a governor which cuts the power when a certain number of rpm is reached
Engine speed sensor
In most cases, a Magnetic pick-up that scans the Flywheel teeth and produces one output signal per scanned tooth, or a Hall generator in the distributor, whose signals are passed to the Electronic control unit
Engine subframe
A separate frame in which the engine is mounted
Engine temperature sender
The engine temperature switch and sending unit measure the temperature of the engine’s coolant. They send this information to the engine temperature warning light and engine temperature gauge, respectively. Compare to coolant temperature sensor (CTS) which transmits the coolant temperature to the computer, and the radiator fan switch which engages the radiator’s cooling fan.
Enginetemperature sensor
A detection device used to monitor the temperature of the engine
Engine timing
  1. The point of time when the spark ignites the air/fuel mixture (ignition timing)
  2. The setting of the valves when they open or close (Valve timing)
Engine tune-up
A procedure for inspecting, testing, and adjusting an engine, and replacing any worn parts, to restore the engine to its best performance
Engine type
Over the years of engine development, several types or configurations have been made. All of them relate to the position of the valves and the camshaft(s) that operates them.

Engine warning light
Engler viscosity
A viscosity obtained by dividing the out-flow time in seconds for 200 ml. of the material being tested, by the time in seconds for 200 ml. of water at 20°C to flow out of an Engler viscosimeter.
Making the air/fuel mixture richer, i.e., increasing the fuel content.

Enrichment circuit
A carburetor system with a plunger to open and close an air-fuel circuit which discharges a rich mixture into the throat of the carburetor for cold starting.
Enrichment device
A circuit in a carburetor providing a richer mixture, operated by engine vacuum
Enrichment system
On a carburetor, any device or system which richens the air/fuel mixture for starting, warm-up or acceleration. Also, in some turbocharged systems, an auxiliary fuel injection system designed to add extra fuel to the intake mixture only under boost conditions.
Enrichment unit
A circuit in a carburetor providing a richer mixture, operated by engine vacuum
A fuel plunger which is used in a carburetor in place of a Choke. By activating the plunger more gas is permitted into the Intake area to enrichen the fuel-air mixture for easier starting.


Total amount of heat in one pound of a substance calculated from accepted temperature base. Temperature of 0°C is the accepted base for water vapor calculation. For refrigerator calculations, the accepted base is -40°C.
to add or suspend bubbles or particles in a moving fluid
One who undertakes ownership of a business or enterprise
A person’s ability to organize, manage, and assume risks of operating a business
Mathematical factor used in engineering calculations. Energy in a system.
Entry EGR System
Entry-level version
Basic model suitable as someone’s first car
Entry model
Basic model suitable as someone’s first car
Entry system
  1. A thin rubber wrapper that surrounds the tread, sidewall and is tucked inside the curing rim during the pre-cured cold process retreading. It protects bonding materials from humidity within the chamber.
  2. A cover enclosing something entirely, such as the glass of a lamp bulb.
Envelope body
A car body whose sides have no visual or actual side-surface interruptions or breaks.
Envelope separator
A porous plastic separator used in maintenance-free batteries to enclose the individual plates completely
Enveloping body
The surrounding conditions.
Environmental assessment
(EA) The study of the impact on wildlife, wetlands, cultural resources, farmland, water and air quality and other environmental issues.
Environmental Impact Statement

  1. An analysis of the environmental impacts of proposed land development and transportation projects; conducted for federally funded or approved projects per NEPA. A draft EIS is circulated to the public and agencies with approval authority for comment.
  2. A report that documents the information required to evaluate the environmental impact of a project. It informs decision makers and the public of the reasonable alternatives that would avoid or minimize adverse impacts or enhance the quality of the environment.
Environmentally aware
An awareness of the dangers and threats to the environment caused by vehicle use and the taking of appropriate action to avoid them
Environmentally friendly
Something that is harmless to the environment, or causing as little harm as possible
Environmental Policy Act
Environmental Protection Act
Environmental Protection Agency
(EPA) A U.S. federal agency charged with protecting the natural resources on the nation.

Environmental Protection Agency certification files
Computer files produced by the EPA for analysis purposes. For each vehicle make, model and year, the files contain the EPA test MPGs (city, highway, and 55/45 composite). These MPG’s are associated with various combinations of engine and drive-train technologies (e.g., number of cylinders, engine size, gasoline or diesel fuel, and automatic or manual transmission). These files also contain information similar to that in the DOE/EPA Gas Mileage Guide, although the MPGs in that publication are adjusted for shortfall.
An awareness of the dangers and threats to the environment caused by vehicle use and the taking of appropriate action to avoid them
Complex organic substance, originating from living cells, that speeds up chemical changes in foods. Enzyme action is slowed by cooling.
Abbreviation for Emergency Operations Center
Abbreviation for End-of-the-line terminal. A local terminal which handles the pick-up and delivery of the customer’s freight (as opposed to a consolidation center). Also referred to as a satellite terminal or group terminal.
Abbreviation for enhanced oil recovery
Abbreviation for European On Board Diagnostics
Abbreviation for Engine Oil Pressure
Abbreviation for Exhaust Oxygen Sensor
Abbreviation for Engine Oil Temperature
  1. Abbreviation for Exhaust Pressure
  2. Abbreviation for Extended Protection as extra warranty esp. on car rental
  3. Abbreviation for Extra Protection as extra warranty esp. on car rental
  1. Abbreviation for Energy Protection Agency.
  2. Abbreviation for the U.S. federal Environmental Protection Agency which is responsible for recommending environmental legislation and in the automotive sphere produces test cycles and estimates fuel economy. It is also charged with protecting the natural resources on the nation.
EPA composite MPG
The harmonic mean of the EPA city and highway MPG, weighted under the assumption of 55 percent city driving and 45 percent highway driving.
Abbreviation for Energy Policy Act of 1992 Comprehensive energy legislation that is expected to expand natural gas use by reforming PUHCA restrictions, allowing wholesale electric transmission access and providing incentives to developers of clean fuel vehicles.
EPA estimate
An American organization (Energy Protection Agency) which determines the fuel consumption of various vehicles. It takes into account city and highway driving. These figures may be helpful in comparing one vehicle against another. Your vehicle can greatly exceed these estimates with sensible driving, the use of cruise control obeying the Speed limits avoiding rapid starts, coasting long before a stop light or sign.

EPA estimates
An American organization (Energy Protection Agency) which determines the fuel consumption of various vehicles. It takes into account city and highway driving. These figures may be helpful in comparing one vehicle against another. Your vehicle can greatly exceed these estimates with sensible driving, the use of cruise control obeying the Speed limits avoiding rapid starts, coasting long before a stop light or sign.

EPA fuel economy
Laboratory fuel economy tests administered by the Environmental Protection Agency (EPA) using simulated weight and Drag to re-create real driving conditions. The city fuel-economy test, also used to test emissions Compliance is based on a drive through typical Los Angeles urban traffic of the 1980s. Such conditions in LA are no longer present. The highway test uses a higher, steadier speed averaging 79.5 kph (49.4 mph).
  1. Abbreviation for Electrostatic Powder Coating
  2. Abbreviation for Electronic Pressure Control — controls line pressure in the auto transmission
Abbreviation for Explosion-proof fan-cooled’ electric motor housing
EP gear oil
An extreme pressure gear oil preventing metal-to-metal contact, used mainly in Gearboxes and final drive units. Also called EP lubricant
A colloquial bicycle term for a remarkable mountain bike ride for either length, elevation gain, or spectacular views
Epicyclic gear
A Gear that operates around the circumference of another
Epicyclic gearbox
A form of gear used by Benz in which small Pinions revolve around a central or Sun gear and mesh with an outer Ring gear called the annulus. Type used in the Ford Model T. Also called Planetary gearset, planetary transmission, or sun-and-planet gears.
A geometric path followed by a specific point located in a generating circle which is rolled around the Periphery of a Base circle.
A part of a circle which is not on the circumference of another circle around which it turns
EP lubricant
Abbreviation for Explosion-proof non-ventilated’ electric motor housing
Abbreviation for EGR Valve Position Sensor (Ford)
Synthetic plastic adhesive.
Epoxy adhesive
Adhesives which offer a combination of high room temperature strength with good load bearing properties. These adhesives have exceptional adhesion to metal surfaces
Epoxy resin
A thermosetting resin based on ethylene oxide or similar materials or derivatives, used in adhesives, fillers, and Primers and other finishes
  1. Abbreviation for Evaporator pressure regulator valve.
  2. Abbreviation for Exhaust pressure regulator
Abbreviation for Erasable Programmable Read Only Memory
EPR system
Abbreviation for Evaporator pressure regulator
Abbreviation for electronically controlled power steering. EPS is used in more expensive models, such as the BMW Servotronic system where the assistance provided alters according to the speed at which the car is traveling
Abbreviation for EGR Pressure Transducer — replaced by PFE
Equalized Valve In Receiver
A bracket or cable connector which balances tension equally on the cables to the parking brakes.

Equalizer line
In air conditioner system, a line or connection used to operate certain control valves. Little or no refrigerant flows through the line
Equal length header
An exhaust manifold where the runners from each cylinder are of equal length. Such a system allows exhaust pulses to meet at the collector or single pipe in a controlled sequence, thus enhancing cylinder evacuation and gas flow.
Equal power distribution
A system in four-wheel drive vehicles which ensures that an equal amount of power is passed to the front and rear wheels
Equal power split
A system in four-wheel drive vehicles which ensures that an equal amount of power is passed to the front and rear wheels
Equilibrium reflux boiling point
(ERBP) The boiling point of a brake fluid as determined by a special test procedure. Both dry and wet ERBPs are used in evaluating brake fluids.
Devices and systems fitted to a vehicle which are either essential or optional, and either fitted by the manufacturer (Original equipment) or subsequently by the owner (Aftermarket equipment).

Equipment daily inspection and condition report
The pre-trip inspection form used by drivers to perform equipment inspections on their tractors and trailers.
Equipment dump
Equipment hauling flatbed trucks. Also called equipment loader.
Equipment Loader
Equipment hauling flatbed trucks. Also called equipment dump.
Equipment Manufacturer
Equipment Manufacturer Vehicle
Equipment package
A combination of equipment provided by the manufacturer
Equivalence ratio
(ER) The ratio of the Stoichiometric oxidizer to fuel ratio (O/F) of a particular oxidizer and fuel to the actual oxidizer to fuel ratio at which the unit is operating. This is a measure of the fuel rich condition of a system (ER more than 1 is fuel rich while ER less than 1 is fuel lean). For example, in a pure oxygen and hydrogen system, the stoichiometric O/F is 8:1. Therefore, a unit operating at a ratio of 4:1 has an equivalence ratio of 2.0 (fuel rich).
Equivalent braking force
Equivalent Unit
  1. Abbreviation for Equivalence ratio
  2. Abbreviation for an ellipsoidal reflector lamp
Abbreviation for Equilibrium reflux boiling point
The process of hoisting into place and bolting the various parts of a ship’s hull.
The cgs unit of energy or work equal to the work done by a force of one dyne acting over a distance of one centimetre.
[Gr. lit The law of work] Technically, it means the biotechnology study of how human beings relate to their surroundings and how efficiently they perform in that environment. However, the meaning has also come to be used in a qualitative sense so that a vehicle has good or bad ergonomics meaning that the controls, switches, instruments, seats, pedals, and steering wheel suit the human driver.
Ergopower shifter
Campagnolo’s integrated bicycle brake levers/shifter levers which provides the ability to shift gears without taking your hands off the handlebars.
To remove a surface layer (by chemical action or by rubbing)
Eroded crown
A condition of the top of a piston caused by detonation or preignition where temperatures are raised so high that part of the piston crown is melted away.
Eroded piston
A condition caused by detonation or preignition where temperatures are raised so high that part of the piston crown is melted away.
A reduction in size of an object because of a liquid or gas impact on the object.
Erosion control
Protecting the exposed surfaces of roadway slopes from harmful effects of runoff water and rain.
Error Ratio
Abbreviation for Electronic Spark Advance
Abbreviation for Electronic Spark Control
Abbreviation for Electronic Stability Control. When a vehicle strays from the intended travel path or begins to spin out, the ESC automatically brakes individual wheels or reduces throttle to keep the vehicle under control. The system was first introduced by Mercedes Benz in 1994. Although it has been phased in on a number of vehicles (particularly cars and SUVs), it is required on all vehicles in Canada, USA, Australia, and Europe beginning in 2012.
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Cadillac Escalade

A model of automobile manufactured by the Cadillac division of General Motors from 1999-current. It also includes the Escalade ESV and Escalade EXT

Escape Ramp
Escape trunk
A vertical trunk fitted with a ladder to permit personnel to escape if trapped
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A model of automobile manufactured by Ford

A panel or part used to hide or protect another part. For instance a window handle may reveal its attaching bolt and the hole in the door panel, so an escutcheon disc is used to cover the hole. Some are decorative as well as functional.
Escutcheon Pin
A piece generally used to join a plate or shield, to cover or protect softer or more delicate materials or actions.
Abbreviation for Electrostatic Discharge
Abbreviation for Early Suppression, Fast Response. A ceiling-mounted sprinkler systems that started being used in warehouses around 1990 as an alternative to rack-mounted sprinkler systems. ESFR heads detect fire faster and are reported to start spraying with more speed than conventional sprinkler heads. They also output water at higher volumes (approximately 100 gallons per minute). Droplet size is typically bigger which delivers more water, with greater speed, to the fire source. ESFR systems reportedly extinguish fires faster and more effectively with less damage to product than in-rack systems.
Abbreviation for Chrysler’s electronic shift module — part of transmission shifter assembly
Abbreviation for electric Sunroof
  1. Abbreviation for engine speed sensor
  2. Abbreviation for Electronic Spark Selection (Cadillac)
Abbreviation for Electronic spark timing system
Smallest operating entity producing a homogenous set of goods and services and is capable of reporting full range of production account variables to calculate value added.

Estate car
A British term for a station wagon, or four-door, four passenger car with an extended roof line plus a gate or hatch in the rear for increased cargo capacity.
An organic compound formed by reacting an acid with an alcohol, always resulting in the elimination of water.



A guess on the part of a service department with respect to the nature of a vehicle’s problem and cost of repairing it. Although most shops will stand by their estimate, there is also the situation where the problem is caused by something which will be more expensive to repair or may be less expensive. In the case where other components are also faulty (but the estimate did not include them), the shop may contact the Customer with a revised estimate saying, ‘We can repair what we thought was the faulty part, but we found another defective part which also contributed to the problem once we took things apart. Now the cost will be more. Do you want us to go ahead and repair that component too?’ In the case where a lesser solution repaired the problem, good shops will give you a bill that is much less than the estimate with an explanation like, ‘We thought we had to replace the expensive control box, but we found that one of its plugs had come loose’.

Abbreviation for Experimental Safety Vehicle
Abbreviation for Elapsed time. The length of time it takes a Dragster to complete the one-fourth mile run.
Abbreviation for expected time of arrival.
Abbreviation for ethyl tertiary butyl ether (CH3)3COC2H. An oxygenate blend stock formed by the catalytic etherification of isobutylene with ethanol
  1. Abbreviation for Electronic Traction Control
  2. Abbreviation for Electronic Temperature Control
  1. A roughening or disintegration of the paint surface, which can occur on small patches or over a wide area, through attack from bird droppings, soap deposits, industrial fallout, etc. Also called lifting.
  2. The removal of soil or the natural oxide film from an aluminum surface, giving a roughened surface which improves adhesion of the subsequent paint layer, or removal of the actual metal.
  3. A system of marking car windows with the registration number so as to deter thieves.
Etching primer
A Primer for aluminum which has an etching effect to improve adhesion
Etch primer
A Primer for aluminum which has an etching effect to improve adhesion
(C2H6) A normally gaseous straight-chain hydrocarbon. It is a colorless paraffinic gas that boils at a temperature of -88.6°C. It is extracted from natural gas and refinery gas streams. It is a refrigerant (R-170) sometimes added to other refrigerants to improve Oil circulation.
(CH3-CH2OH) A clear, colorless, flammable oxygenated hydrocarbon. Ethanol is typically produced chemically from ethylene, or biologically from fermentation of various sugars from carbohydrates found in agricultural crops and cellulosic residues from crops or wood. It is used in the United States as a gasoline octane enhancer and oxygenate (blended up to 10 percent concentration). Ethanol can also be used in high concentrations (E85) in vehicles designed for its use. The lower heating value, equal to 76,000 Btu per gallon, is assumed for estimates in the Renewables Energy Annual report. Also known as Ethyl Alcohol or Grain Alcohol

A generic term applied to a group of organic chemical compounds composed of carbon, hydrogen, and oxygen, characterized by an oxygen atom attached to two carbon atoms (e.g., methyl tertiary butyl ether).

Oxygenation of an Olefin by methanol or ethanol. For example, MTBE is formed from the chemical reaction of isobutylene and methanol
Ethyl acrylate
A Polymer used in toughening rubber
Ethyl Alcohol


An Olefinic hydrocarbon recovered from refinery processes or petrochemical processes. Ethylene is used as a petrochemical feedstock for numerous chemical applications and the production of consumer goods.
Ethylene dichloride
A colorless, oily liquid used as a solvent and fumigant for organic synthesis, and for ore flotation.
Ethylene glycol
A chemical solution added to the cooling system to protect against freezing.


Ethyl Ester
A fatty Ester formed when organically derived oils are combined with ethanol in the presence of a catalyst. After water washing, vacuum drying, and filtration, the resulting ethyl ester has characteristics similar to petroleum-based diesel motor fuels.

Ethyl gasoline
gasoline to which ethyl fluid (Tetraethyl lead ethylene dibromide, ethylene dichloride, or another octane improver) has been added to improve the gasoline’s resistance to knocking. It slows down the burning rate thereby creating a smooth pressure curve that will allow the gasoline to be used in high compression engines. It is a generic term describing premium or high-octane fuel. It was first sold in 1924.
Ethyl Tertiary Butyl Ether
(ETBE) An Aliphatic ether similar to MTBE. This fuel oxygenate is manufactured by reacting isobutylene with ethanol. Having high octane and low volatility characteristics, ETBE can be added to gasoline up to a level of approximately 17% by volume. ETBE is not yet commercially available.
Abbreviation for EGR Pressure Transducer
  1. Abbreviation for Evaporator temperature regulator valve
  2. Abbreviation for Electronically Tuned Receiver
  3. Abbreviation for Emergency Transportation Route
Abbreviation for European Tyre and Rim Technical Organisation.
Abbreviation for European Union
Abbreviation for Energy utilization index
Euromix formula
The basis for a standard test cycle covering both town driving and driving on the open road. In North America a similar is called the Town and Country Formula
Organization operating rail passenger services from Europe to mainland UK.
That certain mixture of two substances providing lowest melting temperature of all the various mixes of the two substances.
Eutectic alloy
A mixture of metals which has a melting point lower than that of any of the metals in the mixture, or of any other mixture of these metals.
Eutectic point
Freezing temperature for eutectic solutions.
Abbreviation for Electric Vehicle — A vehicle powered by one or more electric motors rather than by an internal combustion engine. The most common source of electricity is chemical storage batteries.
  1. To remove by pushing out.
  2. To create a vacuum in an air conditioning system to remove all traces of air and moisture.
  3. To pump the air, moisture and foreign material out of the system with a vacuum pump. Also called Pump down
Evacuated-tube collector
A collector in which solar thermal heat is captured by use of a collector fluid that flows through an absorber tube contained inside an evacuated glass tube.
Removal of air (gas) and moisture from a refrigeration or air conditioning system.
Abbreviation for Evaporative emission control system — Prevents the escape of fuel vapor to the atmosphere
Abbreviation for Evaporative Canister Purge
Abbreviation for Evaporative Emissions System Canister Vent
To turn into a vapor
The process of changing from a liquid to a vapor, such as boiling water to produce steam; evaporation is the opposite of Condensation. Heat is absorbed in this process of evaporation. Evaporation can occur at various temps, depending on the liquid and the pressure. Also refers to Solvents in the paint escaping to the air.

Evaporation control system
(EVAP or ECS) A system for reducing evaporative emissions by means of a sealed fuel tank, a vapor-liquid separator, a three-way valve, an activated carbon filter, and a network of interconnecting hoses. A system used to prevent the escape of gasoline vapors to the atmosphere from the fuel tank and carburetor. Also called ‘evaporative Emission Control system’
Evaporation system
Evaporative condenser
Device which uses open spray or spill water to cool a condenser. Evaporation of some of the water cools the condenser water and reduces water consumption.
Evaporative emissions canister
Evaporative emission control system
(EVAP or EEC) A system for reducing evaporative emissions (fuel vapor escaping into the atmosphere) by means of a sealed fuel tank, a vapor-liquid separator, a three-way valve, an activated carbon filter, and a network of interconnecting hoses. Also called evaporation control system
Evaporative emissions
Vapors or fumes not emitted by the exhaust system, but escaping from the fuel tank, carburetor and crankcase, and accounting for about 40% of hydrocarbon emissions released by a gasoline engine without emission controls
Evaporative emission shed system
(EESS) a Ford evaporative emission control system introduced in 1978
Evaporative losses
Vapors or fumes not emitted by the exhaust system, but escaping from the fuel tank, carburetor and crankcase, and accounting for about 40% of hydrocarbon emissions released by a gasoline engine without emission controls
The unit in an air conditioning system used to transform refrigerant from a liquid to a gas. It is at this point that cooling takes place as heat is removed from the air. An air conditioning system component through which cool, liquid refrigerant is pumped at a reduced pressure. When heated by the warm passenger compartment air being forced through the evaporator, the refrigerant evaporates, drawing heat from the air as it passes over the cooling fins. Opposite to condenser.

Evaporator, dry type
Evaporator in which the refrigerant is in the liquid droplet form.
Evaporator equalized valve in receiver
(EEVIR) A unit similar in design to a valve-in-receiver type, except that it has an equalizer port of the expansion valve that allows for faster reaction time
Evaporator fan
Fan which increases airflow over the heat exchange surface of evaporators.
Evaporator, flooded
Evaporator containing liquid refrigerant at all times.
Evaporator pressure regulator
(EPR) Automatic pressure regulating valve mounted in suction line between evaporator outlet and compressor inlet. Purpose is to maintain a predetermined pressure and temperature in the evaporator.
Evaporator pressure regulator valve
(EPR) An evaporator temperature control device regulated by back pressure. Used on an older Chrysler Corp. system. Located in the compressor inlet. A system using this device is referred to as an EPR system
Evaporator temperature regulator valve
(ETR) A temperature-regulated evaporator temperature control device used on some early model Chrysler Corp. systems
EVAP system
Abbreviation for Evaporative Emission Control System
Abbreviation for Exhaust Valve Closes
Even keel
A ship at even keel is when the keel is horizontal or parallel to the surface of the water.
Event Data Recorder
(EDR) A device which is sometimes called an automobile black box which records a number of critical functions of the engine and drivetrain.
Abbreviation for Electronic Vehicle Information Center
Evil Kenivel
Trucker slang for a motorcycle policeman as in ‘There’s an Evil Kenivel taking pictures at the 38.’
  1. Abbreviation for Exhaust Valve Opens
  2. Abbreviation for Electronic Vehicle Orifice
(Evo) When Harley-Davidson began using aluminum to build its cylinder jugs, it called this new engine the Evolution
Abbreviation for EGR valve position sensor
  1. Abbreviation for Electronic voltage regulator
  2. Abbreviation for EGR Vacuum Regulator
  3. Abbreviation for Electronic Vacuum Regulator
Electronic vacuum regulator valve
Abbreviation for Electromagnetic Valve Train.


Abbreviation for electric windows

Abbreviation for excellent, as in exc condition.
A vehicle brand of which the 1965-69 model II Series I are milestone cars.
Removal of excess earth from roadway in preparation for new vertical and horizontal alignments.
  1. A shortage, overage, or damage to a shipment.
  2. A notation of such conditions on a freight bill, bill of lading or unloading checksheet.
Excess air
Air which passes through the combustion chamber and any flues in excess of that which is theoretically required for complete combustion.
Exchange engine
A replacement engine which is provided in exchange for a worn engine while the original engine is being rebuilt
Exchange Membrane
Exchange Membrane Fuel Cell
Exchange Pallet
A pallet intended for use among a designated group of shippers and receivers where ownership of the pallet is transferable with the ownership of the unit load; common pool pallet.
Exchange process
The 1925-1948 models with required application are classic cars.
Excitation current
The electric current in the shunt field of an electric motor resulting from voltage applied across the field
Excitation winding
To pass an electric current through a unit such as the Field coils in the Generator.
Exciter coil
A primary coil which provides stepped up voltage to a second coil.
Exciter winding
A vehicle which had been used as a Demonstrator and is now available for sale
The outermost section of a Turbine wheel, used to purge the turbine of exhaust gases
Executive car
A large, powerful luxury car considered suitable for a business executive
Executive Orders 12759 and 12844
Two Presidential orders which establish requirements for federal agencies to purchase AFVs. Order 12844 accelerates agency acquisitions by 50% beyond requirements contained in Section 303 of the Energy Policy Act for fiscal years 1993-1995, subject to the availability of funds.
Exempt Carrier
A company which transports commodities exempted from Interstate Commerce Commission (ICC) economic regulation.
Exempt Commodity
One that may be transported in interstate commerce without operating authority or published rates.
Slow flow of air from the building to the outdoors.
Abbreviation for Exhaust


  1. To expel spent fumes.
  2. The spent fuel after combustion takes place in an internal combustion engine. Sometimes it refers to the exhaust system.
Exhaust air
Air removed from a space and not reused.
Exhaust back pressure
Any pressure holding back the flow of the gases in an exhaust system. Pressure exerted in exhaust system in reverse direction. Also called back pressure
Exhaust back pressure transducer valve
(BPV or BPS) a device used to sense exhaust pressure changes and control vacuum to the EGR valve in response to these changes
Exhaust Brake
An engine device which changes exhaust pressure to assist in slowing down a vehicle. Also called an exhaust retarder
Exhaust cam
A separate camshaft controlling the opening and closing of the exhaust valves used in twin overhead camshaft engines
Exhaust camshaft
A separate camshaft controlling the opening and closing of the exhaust valves used in twin overhead camshaft engines
Exhaust chamber
Part of the two-stroke exhaust system designed to maintain a specified back pressure
Exhaust Control System
Exhaust cutout
A Y-shaped device that is placed in the exhaust pipe ahead of the muffler. The driver may channel the exhaust through the muffler or out the other leg of the Y where the exhaust passes out without going through the muffler.


Exhaust donuts
The small rubber hangers used to suspend the exhaust system from the chassis pan
Exhaust emission
Exhaust emission control
Click to supersize Emission Controls
Exhaust emission controls
Systems or adjustments designed to limit noxious gases in an engine’s exhaust. Such controls can be grouped into two broad categories those designed to reduce or eliminate the formation of harmful pollutants in the engine itself (e.g., retarded spark setting) and those designed to destroy or otherwise alter the pollutants after they have been formed (e.g., Air injection, Thermal reactors, and Catalytic converters). Evaporative emission controls prevent gasoline vapors from escaping into the atmosphere from the fuel tank and carburetor and crankcase controls recycle fumes from the crankcase through the engine.

Exhaust emission control system
A general term for any system that reduces the harmful exhaust emissions of a motor vehicle, including one or all of the following systems catalytic converter (with or without oxygen sensor air/fuel control), exhaust gas recirculation, secondary air injection or induction, and positive crankcase ventilation
Exhaust emissions
The unburned Hydrocarbons, Carbon monoxide, Oxides of nitrogen, and other noxious gases emitted when gasoline is burned in an engine.
Exhaust engine
Exhaust gas
Gas which is the product of the combustion process and which is passed out of the cylinder through the exhaust valve or port into the exhaust system.

Exhaust gas aftertreatment
Exhaust gas analyzer
An instrument for determining efficiency with which an engine is burning fuel. It determines the exact amounts of hydrocarbons and carbon monoxide in the exhaust.

Exhaust-gas analyzer
An instrument used to measure the exhaust gases (in parts per million, percent, grams per kilometre, or grams per mile) to determine both combustion efficiency and the amount of pollutants in the exhaust.
Exhaust gas check valve
(EGC) a device that allows air injection system air to enter the exhaust manifold, but prevents a reverse flow in the event of improper operation of other components
Exhaust gases
The burned and unburned gases which are expelled out of the exhaust system after combustion takes place.

Exhaust gas oxygen sensor
(EGO) a detection device that changes its output voltage as the exhaust gas oxygen content changes when compared to the oxygen content of the atmosphere. This constantly changing voltage signal is sent to the processor for analysis and adjustment to the air/fuel ratio.

Exhaust gas purification system
An emission control system for diesel engines, which may consist of an Exhaust scrubber, a diesel exhaust filter, and/or a catalytic converter
Exhaust gas recirculation
Exhaust-gas recirculation
(EGR) An emission control system where some of the exhaust gases are rerouted from the exhaust manifold into the combustion chamber to make sure that all fuel is burned before entering the atmosphere. The process lowers the combustion temperature and reduces the formation of oxides of nitrogen (NOx) in the exhaust.
Exhaust gas recirculation system
(EGR) a system used to control oxides of nitrogen (NOx) the exhaust gases are recirculated, lowering the engine combustion temperature, thereby reducing engine pollutants
Exhaust gas recirculation valve
A valve which admits exhaust to the incoming air/fuel mixture
Exhaust header
Steel tubing connecting pipes between the exhaust ports and the exhaust pipe. Usually a header has been polished to allow for better flow of the exhaust.

Exhaust heat
Waste heat produced by a mechanical, chemical, or electrochemical process.
Exhaust heat control valve
(HCV) a valve which routes hot exhaust gases to the intake manifold heat riser during cold engine operation. Valve can be thermostatically controlled, vacuum operated or computer controlled

Exhaust heat recovery
The use of by-product heat as a source of energy.
Exhaust manifold

Exhaust ManifoldExhaust Manifold

  1. The connecting pipes between the exhaust ports of each cylinder and the exhaust pipe. It is usually made of cast iron. Sometimes called the Exhaust header but it is usually made of steel tubing.
  2. A set of pipes or a casting connected to the combustion chamber that carry exhaust gases from the engine to the exhaust system and out of the car through the tailpipe.
Exhaust note
The sound coming from the end of the exhaust pipe. It is usually described as pleasant, loud, throaty, or sporty.
Exhaust oxygen sensor
A detection device that monitors the amount of oxygen in the exhaust stream and sends that information the ECM. Also called an oxygen sensor or an O2 sensor
Exhaust pipe

Exhaust pipeExhaust pipe

Pipe connecting exhaust manifold or header to the muffler.

Exhaust pollutants
Exhaust emissions
Exhaust port

Exhaust portExhaust port

  1. The passage in the cylinder head which connects the exhaust valve and the exhaust manifold. The exhaust gases pass through the port to the exhaust manifold or header.
  2. On two-stroke engines the exhaust port is cut into the cylinder wall because it does not have valves.
  3. That opening which carries the fluid to the downstream pressure of a fluid system.
  4. The opening from which the burnt gases leave the combustion chamber.
Exhaust port timing
The amount of time a two-stroke engine exhaust port is open, expressed in crankshaft degrees or piston travel. Also called Exhaust timing.
Exhaust pressure regulator
(EPR) a device for increasing exhaust backpressure at specific times to increase exhaust flow to the EGR valve
Exhaust pyrometer
An instrument used to measure the temperature of exhaust gases.
Exhaust Retarder
An engine device which changes exhaust pressure to assist in slowing down a vehicle. Also called an exhaust brake
Exhaust scrubber
A diesel exhaust gas purification system which cools the exhaust and separates nitrogen oxide and oil vapors from the gas stream
Exhaust side
The side of the engine where the exhaust valves and exhaust manifold are located
Exhaust stroke

Exhaust strokeExhaust stroke

The fourth stroke of a Four-stroke cycle where the piston moves upward from Bottom dead center to Top dead center and pushes the burned exhaust gases out of the cylinder.

Exhaust system

Exhaust SystemExhaust System

The exhaust port, exhaust valve, exhaust pipe, resonator, catalytic converter, and muffler that carry the exhaust gases from the exhaust manifold out into the atmosphere.

Exhaust timing
  1. Exhaust control system developed especially for two-stroke motorcycle engines in order to enhance low and mid-range power
  2. The amount of time a two-stroke engine exhaust port is open, expressed in crankshaft degrees or piston travel. Also called Exhaust port timing.
Exhaust treatment
Any measures taken to reduce the pollutant concentrations in the exhaust of an internal combustion engine released into the atmosphere
Exhaust tuning
Cutting the exhaust pipe to a length that provides maximum efficiency.
Exhaust turbocharging
Exhaust ultimate power valve
(EXPV) A valve used with an exhaust arrangement that uses a computer which varies the exhaust tube diameter according to engine rpm.
Exhaust valve

Exhaust valveExhaust valve

  1. The valve through which the burned fuel charge passes on its way from the cylinder to the exhaust manifold. It is driven by the camshaft. When comparing an exhaust valve with an intake valve in the same engine, the part of the exhaust valve that seats into the head (i.e., not the stem) will have a smaller diameter than the intake valve.
  2. A movable port which provides an outlet for the cylinder gases in a compressor or engine.
Exhaust valve closes
(EVC) A mark on a valve-timing diagram
Exhaust valve opens
(EVO) A mark on a valve-timing diagram
Freeway or expressway junction. Almost all exits also allow vehicles to join the freeway or expressway. Exits are numbered in both the USA and Canada.
Chemical reaction in which heat is released.
Exotic car
Expensive, low production, rare vehicles with striking shape, size, body construction, engine, etc. Over the years the following vehicles have been called exotic: Aston Martin, DeLorean, DeTomaso Pantera, Dodge Viper, Ferrari, Ford GT, Jaguar, Lamborghini, Lotus, Maserati, Plymouth Prowler, Porsche, and Rolls Royce.
Flatbed or pole trailers that can be expanded beyond its regular length to carry larger shipments.
  1. A ring placed under a piston ring to increase ring pressure on the cylinder walls. For instance an Oil control ring may have an expander ring to assist the oil-control ring to scrape oil off the cylinder wall and provide further sealing.
  2. A device in a drum brake system (either hydraulic or mechanical) which forces the shoes apart into contact with the drum.
  3. A disc used in a wheel cylinder which helps to seal the fit between the cup lips and cylinder walls when there is no pressure in the system.
Expander Ring
A tension ring located under the piston ring that pushes the piston ring out from the piston in order to increase ring pressure on the walls of the cylinder.
Expander spacer
An increase in size, for example when a metal rod is heated, it increases in length and perhaps also in diameter. Expansion is the opposite of contraction.

Expansion And Contraction
Expansion Bolt
A combination of a lag bolt and an internally threaded split sleeve, designed for fastening to stone or concrete by inserting a sleeve into a hole in the concrete and expanding to a tight fit in the hole by turning the lag both with a wrench.
Expansion chamber
A two-stroke engine exhaust system that consists of a header pipe, the first cone, chamber, rear cone, stinger, and silencer.
Expansion Evaporator
Expansion joint
Device in piping designed to allow movement of the pipe caused by the pipe’s expansion and contraction.
Expansion plug
A steel plug, slightly dished or cup-shaped. When driven into place it flattens to fit tightly in its seat. In an engine block, expansion plugs (also called freeze plugs or core-hole plugs) are inserted into the holes in the casting through which core was removed when casting was formed. They open into cooling passages and thus provide pressure relief should the engine coolant freeze and expand.


Expansion stroke
Expansion tank
When the engine is heated, the coolant expands to fill any available space (usually in the radiator). Before the introduction of coolant expansion tanks, the excess coolant was forced out of a vent tube and on the ground. The expansion tank collects the coolant so that when the engine cools off, the resultant vacuum sucks the coolant from the tank back into the radiator.
Expansion Trunk
Raised portion of a tank used on some oil tankers to allow for the expansion of oil when temperature changes.
Expansion tube
A device that converts high pressure liquid refrigerant into low pressure liquid refrigerant (thus lowering its boiling point) before it passes through the evaporator. The expansion valve replaces the thermostatic expansion valve. It is also referred to as a Fixed orifice tube
Expansion valve
A part of an air-conditioning system, located between the condenser and the evaporator that regulates the flow of liquid refrigerant to the vaporator. If cooling needs are low, the valve is almost closed; as additional cooling is required, the valve opens wider so that more liquid refrigerant flows to the evaporator. It reduces the pressure from the high side to the low side and is operated by pressure. Also called an automatic expansion valve (AEV) or thermostatic expansion valve.

Expected residual value
This is the projected or expected value of the vehicle at the end of the lease. Residual value is a measure of the vehicle’s expected depreciation.
Expendable refrigerant system
System which discards the refrigerant after it has evaporated.
Expedited Order
See Emergency order
Moving shipments through regular channels at an accelerated rate.
Expendable Pallet
A pallet intended for a series of handlings during a single trip from shipper to receiver; it is then disposed. see shipping pallet.
Experimental Development Program
Experimental Safety Vehicle
(ESV) A special vehicle built for research into and testing of safety features; (compare SID)
Expiration Date
Date when merchandise is no longer able to be shipped.
Exploded view
A drawing of a mechanism or structure which shows the parts separately but approximately in the position they occupy when assembled
Exploratory well
A hole drilled: a) to find and produce oil or gas in an area previously considered unproductive area; b) to find a new reservoir in a known field, i.e., one previously producing oil and gas from another reservoir, or c) to extend the limit of a known oil or gas reservoir.
A rapid disintegration of an object.

Explosion-proof enclosure
(EXP-PRF) A special enclosed electrical motor housing designed to withstand an internal explosion of specified gases or vapors and allow the internal flame or explosion to escape, usually used in smaller ratings below 1/3 hp if nonventilated (EPNV) and in fan-cooled (EPFC) in larger ratings
Explosive Limit
Explosive rivet
A blind rivet with a hollow shank holding a charge of explosive material. When the rivet is inserted, the shank explodes when you strike the rivet with a hammer thus securing the rivet in place.
Export Letter Of Credit
When an importer has arranged with a bank for letter-of-credit financing of purchases, he applies for issuance of individual letters of credit to cover purchase contracts as made.
Export Restraint
Express Van
Express VanClick image for books on
Express Van

A model of full-size van produced by the Chevrolet division of General Motors from 1996 to 2008

A US multilane highway road with limited access to be used for rapid travel with few interchanges.
Abbreviation for Exhaust ultimate power valve
Abbreviation for exterior.
Extended Cab

Extended CabExtended Cab

A type of pickup truck (by GM) which has a second row of seating; but unlike a crew cab (which has four full size doors) it has a half-door that can be opened only after the main door is opened. The seating is usually a little more cramped than in a crew cab. Also called Club Cab, King Cab, XtraCab, Access Cab, SuperCab, or Cab Plus.

  1. A part which is inserted between a ratchet and a socket to provide access to nuts or bolts which are deeply inset or hard to reach. Also called extension bar or extension piece.
  2. The return or stretching outward of suspension components (after compression) caused by spring pressure.
  3. Longer blades that are used on forklifts when the standard blades are inadequate.
Extension bar
Extension housing
Extension piece


Longer blades that are used on forklifts when the standard blades are inadequate.
Extension screw
Extension spring

Extension springExtension spring

A closed-coiled Helical spring that offers resistance to a pulling force.

Exterior mirror
The mirror that is usually mounted on the door. In Japan (and other countries) it was mounted on the front Fenders. Also called external mirror.
External combustion engine
An engine that burns its fuel outside the engine. A Steam engine is an external combustion engine.
External diameter
The outside diameter of a cylinder, tube, or washer
External drive
Term used to indicate a compressor driven directly from the shaft or by a belt using an external motor. Compressor and motor are serviceable separately.
External drive compressor
External equalizer
Tube connected to low-pressure side of a thermostatic expansion valve diaphragm and to exit end of evaporator.

Externally-balanced crankshaft
A crankshaft that requires external balancing weight, usually on the vibration damper of the Flywheel, for balance
External micrometer
A micrometer for measuring external diameters
External mirror
The mirror that is usually mounted on the door. In Japan (and other countries) it was mounted on the front Fenders. Also called exterior mirror.
External mix air cap
A special type of air cap for spray guns. Air and fluid are mixed in the space outside the air cap, directly in front of the nozzle the most common type of air cap.

External reforming
The production of hydrogen from a hydrocarbon fuel (methanol, gasoline, natural gas, propane, etc.) prior to entry to the fuel cell or stack.
External snap ring
A split ring held in place by its own tension within the grooves cut around a shaft. Compare Internal snap ring.
External thread
Thread consisting of projecting ridges on the outside of a part such as a bolt or screw (which fits into the corresponding internal thread of a nut). Also called male thread
External tooth lock washer

External tooth lock washerExternal tooth lock washer

A hardened circular lock washer with a series of twisted prongs or ‘teeth’ which extend out from the outer edge of the washer. In application, these teeth bite into the nut, bolt, or material to prevent the nut from easily backing out. Compare internal tooth lock washer

External vane pump
A pump with either an elliptic rotating piston or an eccentrically mounted circular rotor
A device for removing some object (e.g., bearing, bushing, sleeve, bolt, stud, etc.).

Extra-Low-Voltage electric circuit
A circuit operating at a voltage up to and including 30 volts.
Optional items either supplied by the manufacturer at the buyer’s request, or added later by the owner. Usually they are things like seat covers, floor mats, additional lights, Sunroof, glass tinting, CD changers, etc.
Extreme-pressure lubricant
(EP lubricant) A Lubricant designed and compounded to withstand very heavy loads imposed on gear teeth.
To form or shape a tube or rod by forcing hot or soft metal, rubber, or plastic through an aperture
A machine that shapes a rubber compound into a usable form. Uncured rubber is heated to soften and forced through dies having the desired shape and dimensions.
A part, like a molding, formed by forcing or extruding the material through a shaped orifice.
Abbreviation for Ex Works which represents the minimum risk and cost for the supplier and the maximum risk and cost for the buyer. The seller’s only responsibility is to make the goods available at his premises. He is not responsible for loading the goods on the vehicle provided by the buyer, unless otherwise agreed.


A circular opening or hole, such as that at the end of a leaf spring or that formed at the end of a cable.

Eye baller
A flashy looking, bright colored, usually a sporty type automobile.
  1. A bolt with a ring-like top in place of a head, through which a cable can be passed, e.g. for lifting purposes
  2. A bolt having a head in the form of an open or closed anchor ring, or of a flattened and pierced section, with or without a collar or shoulder under the head.
A partial round area for vehicle turnaround located adjacent to the serving road that provides access to lots and serves as a vehicle turnaround.
Eye envelope
The oval area on an instrument-panel drawing that theoretically shows the range of human vision. The idea is to keep controls and gauges within the eye envelope.
A frame attachment that allows you to mount racks or Fenders to the bicycle.
Eyelet connector
A connector for electrical connections which is attached to a wire and has its ring-shaped end pushed onto a round post or threaded terminal
Eyelet pliers

Eyelet pliersEyelet pliers

Pliers for punching small holes, with a round stud in one jaw and a hole in the other

Abbreviation for elektrische Zundkontrolle, German for electronically controlled ignition
E-Z Lok
E-Z Lok
An insert for damaged threads. It differs from coil inserts which are steel wires coiled in a spring-like design. E-Z LOK threaded inserts are screw machined out of solid steel.