Through the years," boasted the 1980 full-line catalog. "Cadillac has earned for itself an exclusive place ... a solitary niche ... in the pantheon of the world's truly fine automobiles." Readers were even reminded how Cadillac had twice won the DeWar trophy in the early years of the century, first for its use of interchangeable parts and later, for pioneering the electric self-starter.
This year brought a restyled Brougham and DeVille, with a more formal roofline that gave more space in back. Their new grille was supposed to boost aerodynamic efficiency too. Flush-mounted windshields on Eldorado and Seville added style and helped cut wind noise. Suspension refinements included low-friction ball joints and larger bushings, plus new low-rolling-resistance tires. New options: a three-channel garage door opener and heated outside mirrors.
On the engine roster, the 368 cu. in. (6.0-liter) V-8 with four-barrel carburetor was standard on Fleetwood Brougham, DeVille and limousines. A digital fuel-injected version (with computerized self-diagnostic features) was standard on Eldorado, a no-cost option for Seville. The DFI V-8's memory turned on an "Engine Check" light to warn of malfunctions. Meantime, the engine's microprocessor could make substitutions that might allow the car to continue to run. An MPG Sentinel calculated continual. average and instantaneous miles-per-gallon readings at the touch of a button. Rounding out the lineup, Seville's standard 5.7-liter diesel V-8, manufactured by Oldsmobile, was also available under the hood of Eldorado, DeVille and Fleetwood Brougham. Late in the model year, a Buick 4.1-liter V-6 was added -- the first such offering on a Cadillac, and the first engine other than a V-8 in six decades.
Body colors for 1980 were: Cotillion White; Platinum; Sable Black; Steel Blue; Superior Blue; Twilight Blue; Canyon Rock; Princess Green; Blackwatch Green; Colonial Yellow; Flax; Sandstone; Columbian Brown; Bordeaux Red; Saxony Red; and Norfolk Gray. At extra cost, buyers could have any of five Firemist colors: Azure Blue, Desert Sand, Victoria Plum, Sheffield Gray. or Western Saddle. For rust protection, over 100 areas were specially treated. All lower body exterior panels were made from pre-coated metals. Each point of metal-to-metal contact contained either a gasket or bi-metal molding. All bodies were dipped in electrically charged primer to increase bonding adhesion.
While Brougham and DeVille got a moderate restyle for 1980, Seville changed drastically. Not everyone adored the new "bustleback" body and long hood, or the razor-edge contours reminiscent of 1950s Rolls-Royce bodies. The new Seville had front-wheel drive and, in a surprising move, a standard diesel engine. Sales dropped sharply, and would do so again in 1981, but these were bad years for the industry as a whole.
| Engine | V6 252cc (4.1L) | V8 350cc (5.7L) | V8 350cc (5.7L) Diesel | V8 368cc (6.0L) |
| Crankcase | 4 qt | 4 qt | 6 | 4 qt |
| Crankcase with new filter | 5 qt | 5 qt | 7 | 5 qt |
| AutomaticTransmission after draining | 10 pt | 10 pt | 6 pt | 8 pt |
| Drive Axle | 3.25 pt | 3.25 pt | 4.25 pt | 4.25 pt |
| Fuel tank | 20 gal(US) | 21 gal(US) | 27 gal (US) | 25 gal(US) |
| Cooling with heater | 13.6 qt | 15.5 qt | 23.7 qt | 21.4 qt |
| Cooling with A/C | 13.6 qt | 15.5 qt | 23.7 qt | 21.4 qt |
| Heavy duty Cooling | 14.1 qt | NA | NA | NA |
| Engine V.I.N Code | 4 | 6 | 9 |
| Engine type | V6-252cc(4.1L) | V8-368cc(6.0L) | V8-368cc(6.0L) |
| Fuel delivery | 4 bbl | 4 bbl | DFI |
| Manufacturer | Buick | Cadillac | Cadillac |
| Original Spark plug | R45TSX | R45NSX | R45NSX |
| Gap | 0.060 in. | 0.060 in | 0.060 in |
| Distributor | Electronic | Electronic | Electronic |
| Ignition timing (BTDC) | 15° | 18° | 10° |
| Intake valve opens (BTDC) | 16 | 11 | 11 |
| Fuel pump pressure | 4¼ to 5½ psi | 5½ to 6½ psi | 12 - 14 min. |
| Idle speed | 550 rpm | 575 rpm | 575 rpm |
| Part # | 1102921 | 1101040 | 1101046 | 1101050 | 1101091 |
| Field current @ 12 V | 4 - 4.5 | 4 - 4.5 | 4 - 4.5 | 4 - 4.5 | 4 - 4.5 |
| Output | 63 amps | 70 amps | 80 amps | 100 amps | 100 amps |
| Regulator | Solid state | Solid state | Solid state | Solid state | Solid state |
| Volts @ 75° | 13.8 - 14.8 | 13.8 - 14.8 | 13.8 - 14.8 | 13.8 - 14.8 | 13.8 - 14.8 |
| Engine | V6-252cc (4.1L) | V8-350cc (5.7L) | V8-368cc (6.0L) | V8-350cc (5.7L)Diesel |
| Battery Ampere Hour Capacity | 540 amps cold cranking power @ 0°F | |||
| Battery Volts | 12 | 12 | 12 | 12 |
| Battery Terminal Grounded | Neg. | Neg. | Neg. | Neg. |
| Starter, Lock Test, Amps | Not Recommended | |||
| Starter, Lock Test, Volts | ||||
| Starter, Lock Test, Torque | ||||
| Starter, No-Lead Test, Amps | 65 - 95 | 65 - 95 | 65 - 95 | 40 - 140 |
| Starter, No-Lead Test, Volts | 9 | 9 | 9 | 9 |
| Starter, No-Lead Test, RPM | 7000 - 10500 | 7000 - 10500 | 7000 - 10500 | 8000 - 13000 |
| Starter, Brush Spring Tension | 35 oz. min. | 35 oz. min. | 35 oz. min. | 35 oz. min. |
| Engine V.I.N Code | 4 | 8 | N | 6 | 9 |
| Engine type | V6-252cid(4.1L) | V8-350cc(5.7L) | V8-350cid(5.7L) | V8-368cid(6.0L) | V8-368cc(6.0L) |
| Manufacturer | Buick | Oldsmobile | Oldsmobile | Cadillac | Cadillac |
| Fuel delivery | 4 bbl | EFI | Diesel | 4 bbl | DFI |
| Horsepower | 125@3800 | 160@4400 | 105@3200 | 150@3800 | 145@3800 |
| Torque | 205@2000 | 265@1600 | 206@1600 | 265@1600 | 265@1600 |
| Bore x Stoke | 3.965 x 3.400 | 4.057 x 3.385 | 4.057 x 3.385 | 3.800 x 4.060 | 3.800 x 4.060 |
| Compression Ratio | 8.00:1 | 8.00:1 | 22.5:1 | 8.20:1 | 8.20:1 |
| Oil pressure | 37 psi | 35 psi | 40 psi | 35 psi | 35 psi |
| Engine type | V6-252cc (4.1L) | V8-350cc(5.7L) | V8-350cc(5.7L) Diesel | V8-368cc(6.0L) |
| Main Brg Journal Dia. | 2.4985 | 2.4985 - 2.4995(No. 1: 2.4988 - 2.4998") | 2.9993 - 3.0003 | 3.250 |
| Main Brg Oil Clearance | 0.0003 - 0.0018 | 0.0005 - 0.0021(No. 5 0.0015 - 0.0031in) | 0.0005 - 0.0021(No. 5 0.0015 - 0.0031in) | 0.0001 - 0.0026 |
| Shaft End-play | 0.003 - 0.009 | 0.004 - 0.014 | 0.004 - 0.014 | 0.002 - 0.012 |
| Thrust on No. | 2 | 3 | 3 | 3 |
| Engine type | V6-252cc (4.1L) | V8-350cc(5.7L) | V8-350cc(5.7L) Diesel | V8-368cc(6.0L) |
| Journal Dia. | 2.2487 - 2.2495 | 2.1238 - 2.1248 | 2.1238 - 2.1248 | 2.5000 |
| Oil Clearance | 0.0005 - 0.0026 | 0.0004 - 0.0033 | 0.0005 - 0.0026 | 0.0005 - 0.0028 |
| Side Clearance | 0.006 - 0.023 | 0.006 - 0.020 | 0.006 - 0.020 | 0.008 - 0.020 |
| Engine type | V6-252cc (4.1L) | V8-350cc(5.7L) | V8-350cc(5.7L) Diesel | V8-368cc(6.0L) |
| Piston-Bore Clearance | 0.0013 - 0.0035 | 0.0010 - 0.0020 | 0.0005 - 0.0006 | 0.0006 - 0.0014 |
| Ring Side Clearance: Top Compression | 0.0030 - 0.0050 | 0.0020 - 0.0040 | 0.005 - 0.007 | 0.0017 - 0.0040 |
| Ring Side Clearance: Bottom Compression | 0.0030 - 0.0050 | 0.0020 - 0.0040 | 0.0018 - 0.0038 | 0.0017 - 0.0040 |
| Ring Side Clearance: Oil Control | 0.0035 max. | 0.0006 - 0.0096 | 0.0078 max. | None (side sealing) |
| Ring Gap: Top Compression | 0.013 - 0.023 | 0.010 - 0.023 | 0.015 - 0.025 | 0.013 - 0.023 |
| Ring Gap: Bottom Compression | 0.013 - 0.023 | 0.010 - 0.023 | 0.015 - 0.025 | 0.013 - 0.023 |
| Ring Gap: Oil Control | 0.015 - 0.035 | 0.015 - 0.055 | 0.015 - 0.055 | 0.015 - 0.055 |
| Engine type | V6-252cc (4.1L) | V8-350cc(5.7L) | V8-350cc(5.7L) Diesel | V8-368cc(6.0L) |
| Seat Angle | 45° | exhaust valve seat: 31° | intake: 45°;exhaust: 31° | 45° |
| Face Angle | 44° | exhaust valve face: 30° | intake: 44°;exhaust: 30° | 44° |
| Spring Test Pressure | 164 lb @ 1.34"(exhaust: 182 lb @ 1.34") | 187lb @ 1.27" | 152 lb @ 1.30" | 160 lb @ 1.50" |
| Spring Installed Height | 1-11/32" | 1-43/64" | 1-43/64" | 1-15/32" |
| Stem-to-Guide Clearance: Intake | 0.0015 - 0.0035 | 0.0010 - 0.0027 | 0.0010 - 0.0027 | 0.0010 - 0.0027 |
| Stem-to-Guide Clearance: Exhaust | 0.0015 - 0.0032 | 0.0015 - 0.0032 | 0.0015 - 0.0032 | 0.0012 - 0.0029 |
| Stem Diameter: Intake | 0.3412 | 0.3429 | 0.3429 | 0.3420 |
| Stem Diameter: Exhaust | 0.3412 | 0.3424 | 0.3424 | 0.3418 |
| Engine type | V6-252cc (4.1L) | V8-350cc(5.7L) | V8-350cc(5.7L) Diesel | V8-368cc(6.0L) |
| Cyl. Head Bolts | 80 ft.lb | 130 ft. lb | 130 ft. lb | 95 ft. lb |
| Rod Brg Bolts | 40 ft.lb | 42 ft. lb | 42 ft. lb | 40 ft. lb |
| Main Brg Bolts | 100 ft.lb | 80 ft. lb (No. 5: 120 ft. lb) | 120 ft. lb | 90 ft. lb |
| Crankshaft Damper or Pulley Bolt | 225 ft.lb | 310 ft. lb | 200 - 310 ft. lb | Press fit |
| Flywheel to Crankshaft Bolts | 60 ft.lb | 60 ft. lb | 60 ft. lb | 75 ft. lb |
| Intake Manifold | 45 ft.lb | 40 ft. lb | 40 ft. lb | 30 ft. lb |
| Exhaust Manifold | 25 ft.lb | 25 ft. lb | 25 ft. lb | long bolts: 35 ft.lb;short bolts: 12 ft.lb |
| Carb ID | 17080230 (M4ME) | 17080530 (M4ME) |
| Float Level | 7/16 in | 17/32 in |
| Air Valve Spring | 1/2 turn | 1/2 turn |
| Pump Rod | 9/32 in | fixed |
| Primary Vacuum Break | 0.149 in | 0.142 in |
| Secondary Vacuum Break | 0.136 in | 0.400 in |
| Choke Rod | 0.083 in | 0.083 in |
| Choke Unloader | 0.220 in | 0.260 in |
| Fast Idle Speed | 1450 rpm | 1350 rpm |
| Feature | Eldorado | Full size | Seville |
| Caster Range | 1½°P - 3½°P | 2½°P - 3½°P | 1½°P - 3½°P |
| Caster Pref. | 2½°P | 3°P | 2½°P |
| Camber LH wheel Range | 3/16°N - 3/16°P | 3/32°P to 57/64°P | 3/16°N to 3/16°P |
| Camber LH wheel Pref. | 0° | ½° | 0° |
| Camber RH wheel Range | 3/16°N - 3/16°P | 3/32°P to 57/64°P | 3/16°N to 3/16°P |
| Camber RH wheel Pref. | 0° | ½° | 0° |
| Toe-In | 1/8°P to 1/8°P | 1⁄8 in. | 1⁄8 in.P to 1⁄8 in.P |
| Steering Axis Inclination | 11° | 10-19/32° | 11° |
1980 Cadillac Notes
| Sedan de Ville | ... | 49,188 | ... decreased 44,023 |
| Coupe de Ville | ... | 55,490 | ... decreased 65,700 |
| Fleetwood Brougham Sedan | ... | 29,659 | ... decreased 12,541 |
| Fleetwood Brougham Coupe | ... | 2,300 | ... |
| Eldorado | ... | 52,685 | ... decreased 14,751 |
| Seville | ... | 39,344 | ... decreased 14,143 |
| Series 75 | ... | 2,362 | ... decreased 527 |
1980 Automotive Notes