The Porsche 928 5.0 GT is a grand touring sports car produced by Porsche between 1989 and 1991. Representing the pinnacle of the 928 model line, the 5.0 GT was the most powerful iteration of this front-engined, V8-powered Porsche. Designed as a replacement for the 911, the 928 offered a more luxurious and technologically advanced experience, appealing to buyers seeking a sophisticated sports coupe. While never fully supplanting the 911’s iconic status, the 928 carved out a significant niche for itself, particularly in the North American market, and remains a highly sought-after classic today.
Porsche 928 5.0 GT: A Legacy of Innovation
The 928 was a radical departure for Porsche, moving away from the traditional rear-engine layout and air-cooled flat-six engine. Introduced in 1977, it featured a water-cooled V8 engine, a transaxle gearbox, and a sleek, modern design penned by Wilhelm Lehmann. The 5.0 GT, produced during the final years of the 928’s production run, represented the culmination of years of refinement and engineering development. It was aimed at enthusiasts who desired the ultimate performance and exclusivity from the 928 platform.
Engine & Performance
The heart of the 928 5.0 GT is its 4.9-liter (302.49 cu. in.) V8 engine, designated M28.47. This naturally aspirated powerplant produced 330 horsepower at 6200 rpm and 430 Nm (317.15 lb.-ft.) of torque at 4100 rpm. The engine featured multi-port fuel injection and a 10:1 compression ratio. This resulted in a power-to-weight ratio of 4.8 kg/Hp and a power per liter output of 66.6 Hp/l. The 5.0 GT could accelerate from 0 to 60 mph in approximately 5.5 seconds and achieve a top speed of 170.88 mph (275 km/h). Power is delivered to the rear wheels via a 5-speed manual transmission. The engine’s longitudinal, mid-mounted configuration contributed to the car’s balanced handling characteristics.
Design & Features
The 928 5.0 GT retained the distinctive coupe body style of the 928, characterized by its sleek lines, pop-up headlights, and wide stance. The car offered seating for four passengers, although the rear seats were relatively small. The 5.0 GT featured several enhancements over earlier 928 models, including a more aggressive front spoiler, wider wheels and tires (225/50 ZR16 front, 245/45 ZR16 rear), and upgraded suspension components. Inside, the 5.0 GT offered a luxurious interior with leather upholstery and a comprehensive array of gauges. Safety features included an Anti-lock Braking System (ABS), which was becoming increasingly common on high-performance cars of the era. The car’s independent double-wishbone suspension provided a comfortable ride and precise handling. The overall design philosophy focused on blending performance with grand touring comfort.
Technical Specifications
| Brand | Porsche |
| Model | 928 |
| Generation | 928 |
| Type (Engine) | 5.0 GT V8 (330 Hp) |
| Start of production | 1989 |
| End of production | 1991 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (economy) – extra urban | 9.7 l/100 km (24.2 US mpg, 29.1 UK mpg, 10.3 km/l) |
| Fuel consumption (economy) – combined | 21.9 l/100 km (10.7 US mpg, 12.9 UK mpg, 4.6 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.8 sec |
| Acceleration 0 – 62 mph | 5.8 sec |
| Acceleration 0 – 60 mph | 5.5 sec |
| Maximum speed | 275 km/h (170.88 mph) |
| Weight-to-power ratio | 4.8 kg/Hp |
| Weight-to-torque ratio | 3.7 kg/Nm |
| Power | 330 Hp @ 6200 rpm |
| Torque | 430 Nm @ 4100 rpm (317.15 lb.-ft. @ 4100 rpm) |
| Engine layout | Middle, Longitudinal |
| Engine Model/Code | M28.47 |
| 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 | 1580 kg (3483.3 lbs.) |
| Max. weight | 1920 kg (4232.88 lbs.) |
| Max load | 340 kg (749.57 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.) |
| 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 | 5 gears, manual transmission |
| Front suspension | Double wishbone, Independent coil spring |
| Rear suspension | Double wishbone, Independent coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | Front wheel tires: 225/50 ZR16 Rear wheel tires: 245/45 ZR16 |
| Wheel rims size | Front wheel rims: 7J x16 Rear wheel rims: 7.5J x 16 |
The Porsche 928 5.0 GT represents a high point in Porsche’s engineering history. Its combination of performance, luxury, and advanced technology made it a compelling alternative to other grand touring cars of the era. Despite its relatively short production run, the 928 5.0 GT has become a highly collectible vehicle, appreciated by enthusiasts for its unique character and driving experience.
