Porsche's ultra-high performance models, the 928 GT and the 928 S4, deliver spectacular performance and ultimate luxury.

The 928 GT, with its five-speed transmission, is one of the most sophisticated performance automobiles in the world. Its counterpart, the 928 S4, offers virtually the same kind of performance with the ease of a four-speed automatic transmission.

Both models share Porsche's all-aluminum, four-valve, V-8 engine. The 928 GT is rated at 326 horsepower while the luxury version, the 928 S4, has an impressive 316 horsepower.

The Porsche 928 GT can accelerate to 60 mph in 5.6 seconds and boasts a top track speed of 171 mph. The 928 S4 can reach 60 mph in 6 seconds. Top track speed for the automatic is 165 mph. Both Porsches feature safety and performance systems developed for Porsche race cars and adapted for these production models.

Porsche's automatic variable-ratio, limited-slip differential was first developed for the Porsche 959. It uses electronic controls connected to sensors in the Anti-lock Braking System to adjust the differential locking factor from zero to 100 percent based on inputs that signal differences in speed between the rear wheels. The automatic differential system also receives input on brake use and lateral acceleration.

Working in conjunction with Porsche's exclusive Weissach rear suspension, which provides toe correction in cornering situations, these systems enhance road handling and stability. The two high performance Porsches also come with a tire pressure monitoring system developed for Porsche race cars and offered on the Porsche 959. The system is able to detect slight changes in tire inflation and signal the driver.

Porsche is the only automobile manufacturer to include an airbag supplemental restraint system for both driver and front seat passenger as standard equipment on every car sold in the U.S. Other standard safety features on the 928 series models include an Anti-lock Braking System and high performance ZR- rated steel-belted radial tires.

Other luxury appointments on the 928 series include automatic climate control with separate rear air conditioning leather seats front and rear with full power front seats, a Blaupunkt "Stuttgart" AM/FM digital stereo cassette radio, a 10- speaker hi-fi system and 160-watt amplifier system, three-position Positrol memory for driver's seat and outside mirrors, and a driver diagnostic system for 21 separate items. Both 928 models also have an adjustable steering column and instrument cluster, power windows, cruise control, fold-out armrests in the doors, an electric sliding sunroof, interior light with delayed shut-off and a one-key central locking and alarm system.

Every Porsche model is covered by a transferrable, two-year bumper-to-bumper limited vehicle warranty with unlimited mileage and 10-year rust perforation warranty.