The Porsche 928 is a luxury grand tourer produced by Porsche from 1978 to 1995. Representing a significant departure from the traditional 911, the 928 was intended to be a more modern, comfortable, and technologically advanced sports car. The 928 S4, produced from 1986 to 1991, represents a refinement of the original concept, offering increased performance and improved features. This article focuses on the 5.0 S4 CAT variant, equipped with a 320 horsepower V8 engine and automatic transmission, a model that solidified the 928’s reputation as a capable and sophisticated grand tourer.
Porsche 928 5.0 S4 CAT: A Detailed Overview
The 928 S4 marked a substantial evolution in the 928 lineage. Introduced in 1986, it featured a larger 5.0-liter V8 engine, upgraded suspension, and improved braking systems. The “S4” designation signified “Super 4,” referencing the four-valve cylinder heads. The “CAT” suffix indicates the inclusion of a catalytic converter, reflecting increasing emissions regulations. While never achieving the sales volume of the 911, the 928 S4 remains a highly regarded example of 1980s Porsche engineering, known for its blend of performance, luxury, and distinctive styling.
Engine & Performance
The heart of the 928 5.0 S4 CAT is its 4.957-liter (302.49 cubic inch) naturally aspirated V8 engine, designated M28.42. This engine produces 320 horsepower at 6000 rpm and 430 Nm (317.15 lb.-ft.) of torque at 3000 rpm. The engine utilizes multi-port manifold fuel injection and a dual overhead camshaft (DOHC) valvetrain with four valves per cylinder. This configuration delivers a power-to-liter ratio of 64.6 hp/l. Power is delivered to the rear wheels via a four-speed automatic transmission. Performance figures include a 0-60 mph (0-97 km/h) acceleration time of approximately 6 seconds and a top speed of 265 km/h (164.66 mph). The weight-to-power ratio is 5 kg/Hp, and the weight-to-torque ratio is 3.7 kg/Nm, contributing to its responsive driving experience. The engine requires 7.5 liters (7.93 US quarts) of oil and 16 liters (16.91 US quarts) of coolant.
Design & Features
The Porsche 928 is instantly recognizable for its sleek, aerodynamic coupe body style. Unlike the 911’s rear-engine layout, the 928 features a front-engine, rear-wheel-drive configuration with a longitudinal engine placement. This design contributes to a more balanced weight distribution and improved handling characteristics. The 928 S4 boasts a spacious interior for a sports car, comfortably seating four passengers. Key features of the S4 included upgraded leather upholstery, power windows, power steering (hydraulic), and an anti-lock braking system (ABS). The car’s design prioritized both aesthetics and functionality, with a focus on creating a luxurious and comfortable grand touring experience. The 928’s pop-up headlights were a defining styling element of the era. The car’s dimensions are 4520 mm (177.95 in) in length, 1836 mm (72.28 in) in width, and 1282 mm (50.47 in) in height, with a wheelbase of 2500 mm (98.43 in).
Technical Specifications
| Brand | Porsche |
| Model | 928 |
| Generation | 928 |
| Type (Engine) | 5.0 S4 CAT V8 (320 Hp) Automatic |
| Start of production | 1986 |
| End of production | 1991 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (extra urban) | 10.0 l/100 km (23.5 US mpg, 28.2 UK mpg, 10 km/l) |
| Fuel consumption (combined) | 16.6 l/100 km (14.2 US mpg, 17 UK mpg, 6 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 6.3 sec |
| Acceleration 0 – 62 mph | 6.3 sec |
| Acceleration 0 – 60 mph | 6 sec |
| Maximum speed | 265 km/h (164.66 mph) |
| Weight-to-power ratio | 5 kg/Hp |
| Weight-to-torque ratio | 3.7 kg/Nm |
| Power | 320 Hp @ 6000 rpm |
| Power per litre | 64.6 Hp/l |
| Torque | 430 Nm @ 3000 rpm (317.15 lb.-ft. @ 3000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M28.42 |
| Engine displacement | 4957 cm3 (302.49 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 100 mm (3.94 in.) |
| Piston Stroke | 78.9 mm (3.11 in.) |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | DOHC |
| Engine oil capacity | 7.5 l (7.93 US qt | 6.6 UK qt) |
| Coolant | 16 l (16.91 US qt | 14.08 UK qt) |
| Kerb Weight | 1600 kg (3527.4 lbs.) |
| Max. weight | 1920 kg (4232.88 lbs.) |
| Max load | 320 kg (705.48 lbs.) |
| Fuel tank capacity | 86 l (22.72 US gal | 18.92 UK gal) |
| Length | 4520 mm (177.95 in.) |
| Width | 1836 mm (72.28 in.) |
| Height | 1282 mm (50.47 in.) |
| Wheelbase | 2500 mm (98.43 in.) |
| Front track | 1551 mm (61.06 in.) |
| Rear (Back) track | 1546 mm (60.87 in.) |
| Ride height (ground clearance) | 120 mm (4.72 in.) |
| Minimum turning circle (turning diameter) | 11.7 m (38.39 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission |
| Front suspension | Double wishbone, Independent coil spring |
| Rear suspension | Double wishbone, Independent coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | Front: 225/50 ZR16, Rear: 245/45 ZR16 |
| Wheel rims size | Front: 7J x 16, Rear: 8J x 16 |
The Porsche 928 5.0 S4 CAT represents a high point in the model’s development, offering a compelling combination of performance, luxury, and advanced technology for its time. While ultimately replaced by the 993 generation 911, the 928 remains a beloved and collectible Porsche, appreciated for its unique character and engineering excellence.
