Audi S4
Audi's quattro four-wheel-drive system was standard on the C4 S4/S6; a first-generation Torsen-based system which used the "T-1" automatically biasing centre differential (ATB) was used on vehicles equipped with manual transmissions, while a transfer box based system was used on vehicles equipped with an automatic transmission.
Audi 80
Audi developed a sports version of the Coupé in 1990, called the Audi S2. This replaced the famous Audi Quattro (launched in 1980) and featured the well-proven 2.2-litre in-line five-cylinder 20-valve turbo petrol engine from the Audi 200 20V, which was derived from the engine used in the Audi Quattro. A similar version of the engine was used in the Audi 100 based S4 (the 'Ur-S4'). The S2 came as standard with quattro permanent four-wheel drive, and featured a heavy-duty 5-speed manual transmission, and was capable of 150 mph.