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 A8
The Audi S8 includes a four-cylinder mode with ANC, two elliptical dual tailpipes, dynamic steering, sport differential, adaptive air suspension sport with an S-specific setup, 20-inch wheels, S8 emblems on front brake calipers, optional Audi design selection black/Vermont brown with Carbon twill copper inlays.