Deville Cadillac History 1978

Deville Cadillac Models & History 1978

Several styling refinements hit DeVille (and Fleetwood) for 1978. A new, bolder grille pattern in three-row checkerboard style was repeated to the left and right of the license plate below. The new pattern had fewer (and more square) holes than before. Cadillac’s script was above the grille’s header bar (mounted on the body), on the driver’s side. A new solid-color wreath-and-crest ornament rode the hood. New, extra-slim vertical taillamps in tall chrome bumper tips had thin backup lamps inset in the middle and built-in side marker lamps. Back bumpers were new. DeVille’s padded vinyl roof had a custom-trimmed backlight (rear window). Rust-prevention measures included Zincrometal panels and bimetal (stainless steel on aluminum) moldings, plus microencapsulated epoxy-coated screws in key areas.

Underhood was the 425 cu. in. (7.0-liter) V-8 introduced the year before. Six-way power driver’s seat controls were now in the door armrest. New interiors included seatback pockets. Standard on all models: an AM/FM Signal-Seeking stereo radio with scanner and disappearing antenna. Coupe and Sedan DeVilles also had automatic climate control, power windows, and much more. Sunroof, wire wheel discs and 50/50 Dual Comfort seats were available. Nine interior color selections were offered in new Random velour or Hampton woven cloth. Up to a dozen Sierra Grain leather choices came with color-coordinated carpeting. Options included

  • a custom-trimmed padded vinyl top
  • rear deck accent stripes
  • color-keyed bodyside moldings
  • chromed wire wheels
  • electronic leveling
  • chrome accent moldings.

Coupe DeVille could have the Cabriolet roof package, including a chrome accent strip to highlight the Elk Grain vinyl top, Cadillac crests, and a French seam around the back windows — offered in 16 coordinated colors. A DeVille d’Elegance special edition featured pillow-style 50/50 Dual Comfort seats in new Random velour (antique dark green, light beige, light blue. or dark mulberry). Upper doors and front seatback assist straps wore matching Random velour. High-pile carpeting extended part way up the doors. The glove box door held a “DeVille d’Elegance” insignia, as did the pillar behind back side windows. The hood, door, and decklid were striped. Side moldings held vinyl inserts that matched the body color. Other extras:

  • opera lamps
  • three roof-mounted assist straps
  • door pull handles

The d’Elegance trim package came in 21 body colors. Arriving later were Phaeton packages that featured a simulated convertible top (down to authentic-looking welts and stitching). Offered in Cotillion White, Platinum or Arizona Beige (with contrasting top colors), these were identified by “Phaeton” nameplates on back fenders and wire wheels.


Model No. Style Number Body Type Seating Factory Price Shipping Weight Production Total
6C D47 2-door Coupe 6 $10,444 4163 117,750
6C D69 4-door Sedan 6 $10,668 4236 88,951


Feature Base engine Optional fuel injected engine Optional diesel engine
Type 90-degree, overhead valve V-8. Cast iron block and head
Displacement 425 cu. in. (7.0 liters) 350 cu. in. (5.7 liters)
Bore & stroke 4.082x 4.06 in. 4.057 x 3.385 in.
Compression ratio 8.2:1 22.5:1
Brake horsepower 180 @ 4000 rpm 195 @ 3800 rpm 120 @ 3600 rpm
Torque 320 lbs.-ft. @ 2000 rpm 320 @ 2400 rpm 220 lbs.-ft. @ 1600 rpm
Main bearings Five
Valve lifters Hydraulic
Fuel supply 4 Bbl. carburetor electronic fuel injection Electronic fuel injection
VIN Code S T N


Wheelbase 121.5
Overall length 221.2″
Height 54.4″ (coupe); 55.3″ (sedan
Width 74.6″
Front Tread 61.7″
Rear Tread 60.7″
Standard tire GR78 x 15-B wide WSW


Transmission Turbo Hydra-matic transmission standard on all models; column shift.
Gear ratios (1st) 2.48:1: (2nd) 1.48:1; (3rd) 1.00:1; (Rev) 2.07:1.
Standard axle ratio 2.28:1, with 3.08:1 available
Rear Axle Hypoid rear axle
Steering/Suspension variable-ratio, power assisted
Brakes front disc, rear drum
Ignition HEI electronic ignition.
Fuel tank 25.3 gal.


Fuel-injected V-8 engine $744
Heavy-duty cooling system $41
80-amp alternator $51
Engine block heater $20
California emission equipment $75
Limited slip differential $67
High altitude pkg. $33
Electronic level control $140


DeVille Cabriolet $369
DeVille Cabriolet w/Astroroof $1450
DeVille Cabriolet w/sunroof $1250
DeVille d’Elegance $689
DeVille Custom Phaeton $1929


Astroroof w/full vinyl roof $995
Astroroof (painted $1106
Sunroof w/full vinyl roof $795
Sunroof (painted roof $906
Cruise control $122
Controlled-cycle wipers $32
Rear defogger, grid-type $94
Six-way Dual Comfort power passenger seat adjuster $118-$150
Power 50/50 seat recliner $116
Power 50/50 passenger seat recliner $210-$262
Power passenger seatback recliner, notchback seat $116
Tilt/telescope steering wheel $121
Automatic door locks $114
Illuminated entry system $59
Fuel monitor $29
Theft deterrent system $130
Trunk lid release and power pull-down $80
Opera lamps $63
Twilight Sentinel $54
Guidematic headlamp control $62
Trumpet horn $21
Remote-control right mirror $34
Lighted thermometer on left mirror $27
Lighted vanity mirror, passenger $50
AM/FM stereo radio with digital display; $106
AM/FM stereo radio with digital display w/tape player $106
AM/FM stereo radio with digital display w/CB $281
AM/FM stereo radio with digital display w/tape and CB $427
Firemist paint $163
Padded vinyl roof $215-$222
Front bumper reinforcement $9
Chrome accent molding $85-$100
Accent stripes $53
Door edge guards $11-$18
License frame each: $9
Dual Comfort 50/50 front seats $198
Leather seating area $295-$315
Carpeted rubber front floor mats $31-$34); rear: $15-$21
Trunk mat $12
Turbine-vaned wheel covers $54
Locking wire wheels $541-$595
Locking wire wheel covers $179-$233