Ten years after the first 928 was launched, Porsche unveiled the 928S4. This had a 5.0-litre engine with four valves per cylinder and twin overhead camshafts per cylinder bank. Power rose to 320bhp.
The updated car looked more modern, thanks to smoother and flusher front and rear bumpers and lights, while there was a large black rear spoiler.
Intriguingly, the S4 had an ‘intelligent’ cooling system for the engine. This consisted of horizontal louvres between the front intake and the radiator; these were computer controlled and their angle changed according to coolant temperature. The idea being that the louvres were kept closed as much as possible to ensure the best aerodynamic efficiency; the Cd increased from 0.34 to 0.36 when they were open.
Compression ratio: 10.4:1
Maximum power: 320bhp at 6000rpm
Maximum torque: 430Nm at xxxxrpm
Brakes: Front: 282mm discs; rear: 289mm discs. Servo assisted with ABS
Suspension: Front: Independent with double wishbone, telescopic dampers with co-axial coil springs, plus anti-roll bar
Rear: Independent with lower wishbones, upper transverse link (Porsche-Weissach patent geometry), coil springs, telescopic dampers, plus anti-roll bar
Wheels & tyres: Front: 16x7J with 225/50VR16 tyres. Rear: 16x7J with 225/50VR16 tyres
Top speed: 165mph