1988 Sedan DeVille
The Cadillac deVille (series 6C) had a new V-8 which was nearly 20 percent more powerful and 10 percent larger than the unit it replaced. Yet its fuel economy was virtually unchanged from the 1987 level. The larger V-8 also now had roller lifters and low friction pistons. The de Ville had a revised suspension and engine mount rates as well as revised heater/air conditioner components and electronic cruise control system. Previous options now standard for the de Ville included
1988 Sedan DeVille
The deVille's THM 440 automatic transmission now had a computer-controlled electronic torque management to prevent overstressing of driveline components. Six new exterior colors were introduced for the de Ville. A 4.5 liter V-8 engine identification plaque was added to the decklid. The armrest switch-plate was changed from cherrywood to black for 1988. Among the numerous electronic changes for 1988 found in the de Ville were a higher resolution internal speed sensor and a new under-dash relay center.
The Fleetwood Sixty Special (also series 6C) continued to offer a longer wheelbase than the D'Elegance model with which it shared the same refinements and features for 1988.
| Model | Series Number | Body/Style Number | Body Type | Seating | Factory Price | Shipping Weight | Production Total |
| DeVille | 6C | D47 | 2-door Coupe | 6 | $23,049 | 3437 lb | 152,513 |
| DeVille | 6C | D69 | 4-door Sedan | 6 | $23,404 | 3397 lb | |
| Fleetwood D'Elegance | 6C | B69 | 4-door Sedan | 6 | $28,024 | 3463 lb | |
| Fleetwood Sixty Special | 6C | S69 | 4-door Sedan | 6 | $34,750 | 3547 lb |
| Type | 90-degree, overhead valve, V-8, aluminum block and cast iron cylinder liners, cast iron cylinder heads |
| Displacement | 273 cu. in. (4.5 liters) |
| Bore & stroke | 3.62 in. x 3.31 in. |
| Compression ratio | 9.0:1 |
| Brake horsepower | 155 @ 4000 rpm |
| Torque | 240 lb.-ft. @ 2800 rpm |
| Main Bearings | Five main bearings |
| Valve Lifters | Roller hydraulic valve lifters |
| Fuel Delivery | Digital electronic fuel injection |
| Feature | DeVille & D'Elegance | Sixty Special |
| Wheelbase | 110.8 in. | 116.0 in. |
| Overall length | 202.3 in. | 201.7 in. |
| Height | 55.0 in. | 55.0 in. |
| Width | 71.7 in. | 71.7 in. |
| Front Tread | 60.3 in. | 60.3 in. |
| Rear Tread | 59.8 in. | 59.8 in. |
| Standard Tires | Michelin P205/70R14 | P205/70R14 |
| Transmission | THM 440-T4 automatic four-speed (includes overdrive and viscous converter clutch) |
| Steering | All FWD models: power-assisted rack and pinion |
| Steering Ratios | 19.1:1 |
| Front Suspension | Independent MacPherson strut with coil springs, strut-type shock absorbers and stabilizer bar |
| Rear Suspension | Fully independent with coil springs, automatic level control and strut-type superlift shock absorbers |
| Brakes | Power front disc and rear drum with Taves anti-lock system |
| Body Construction | Integral body-frame |
| Fuel Tank | 18.0 US gal. |
1987