The last evolutionary stage of the 928 model featured flared rear wings, a red light panel at the rear, a rear wing painted in exterior colour, exterior mirrors in the Cup design plus 17" Cup rims as standard. The 5.4-litre engine of the GTS generated 350 hp. The 928 GTS came for sale in late 1991 as a 1992 model in Europe and in spring of 1992 as an early 1993 model in North America. Changed bodywork, larger front brakes and a new, more powerful 5.4 L engine were the big changes.
In 1989, 928 buyers had the choice of the S4 or the GT, a better-equipped, manual-only car. The 928 GT was sportier than the 928 S4. Thanks to various modifications, its power unit generated up to 330 hp. The GT was delivered as standard without side protection strips and with wheels in a unique design. It featured a dogleg manual gearbox, a more aggressive suspension, and special seven-spoke Club Sport wheels
The Clubsport was up to 100 kg (220 lb) lighter and became available in 1988. This model was the toned-down version of the 1987 factory prototype which had a lightened body. In 1987, the factory made five white lightweight S4 models with a manual transmission for racecar drivers. The Special Equipment (SE) was a more complete version of the CS, in which some accessories lost in the CS are added back again.
The 928 S4 variant debuted in the second half of 1986 as a 1987 model, an updated version of the 5.0 L V8 for all markets producing 235 kW; 316 hp (320 PS), sporting a new single-disc clutch in manual transmission cars, larger torque converter in cars equipped with automatic transmission cars and fairly significant styling updates which gave the car a cleaner, sleeker look. S4 was much closer to being a truly world car than previous models with only small differences across markets
To replace the base 928, a refreshed 928 S was released in Europe in the 1980 model year (1983 for North America). The S wore new front and rear spoilers and sported wider wheels and tires, but the main change was a revised 4.7 L engine. In 1985, North America got a new 5.0 L 288 hp 32-valve engine with Bosch LH-Jetronic injection. Mid-year 1986 models incorporated the upgraded suspension and Brembo brakes.
The Porsche 928 was the company’s first production car with a V-8 engine and the only coupe powered by a front-mounted V-8 as of today. Developed in the 1970s as a replacement of the 911, the 928 was eventually sold alongside the rear-engine sports car. Production lasted from 1977 until 1995. What people saw was a sleek if rather heavy-looking 2 + 2 hatchback coupe unlike anything else on the road -- a sort of German Corvette.