When designing the 928, which went into series production as of model year 1978, the focus was on lightweight construction. The doors, front wings and bonnet were therefore made from aluminium instead of sheet steel. Behind the plastic bumpers integrated in the body shape there were also aluminium profiles that could withstand a collision at up to 8 km/h (5 mph) without any damage.
The 928 had round, electrically operated pop-up headlights that were integrated in the wings. The rounded fastback was dominated by the large window of the rear lid.
The 928 models were powered by a water-cooled V8 engine with a 90° cylinder arrangement. The displacement of the power unit was increased from an initial 4.5 litres to 5.4 litres. Power was transmitted according to the transaxle principle.
To improve aerodynamics, the models were fitted with a front and rear spoiler from type 928 S (MY 1979) onwards.
The rear axle of the 928 was a completely new development. What made this double-wishbone suspension – also known as the Weissach axle – unique was its toe-in stabilising effect. This worked more or less as a passive rear-wheel steering and thus made a significant contribution to the active safety of the Gran
928 GT (Spring 1989-MY 1991)
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.
928 GTS (MY 1992-95)
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.
928 GT (kevad 1989–1991)
Pop-up headlights with visible lenses // Rear lid with large rear window // Front and rear aprons made of deformable plastic // Rounded front apron with air intakes for brake cooling // Rear wing made of black polyurethane // Side skirts in exterior colour // Side direction indicators // Twin tailpipe // Option: Side protection strips in exterior colour
928 GTS (1992–1995)
Pop-up headlights with visible lenses // Rear lid with large rear window // Front and rear aprons made of deformable plastic // Rounded front apron with air intakes for brake cooling // Flared wheel arches at rear // Rear wing in exterior colour // Red light panel at rear // Side skirts in exterior colour // Side direction indicators // Exterior mirrors in Cup design // Twin tailpipe