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 A6
It was powered by another version of the 32-valve (four valves per cylinder) 4.2-litre V8 engine (parts code prefix: 077, identification code: AHK, later to be seen in the Audi S8 as AKH). Audi's performance division reworked key parts of the engine, increasing the maximum power to . It was only available with a revised six-speed manual transmission (parts code prefix: 01E, identification code: DGU) (gear ratios – 1st: 3.500, 2nd: 1.889, 3rd: 1.320, 4th: 1.034, 5th: 0.857, 6th: 0.730), with a final drive ratio of 4.111.