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 S1
The Audi S1 is Audi's smallest S model car and a performance version of the Audi A1. The first variant (Typ 8X, produced from 2010 to 2018) has 228 hp (231 PS / 170 kW) derived from the Volkswagen group's EA888 2.0 litre turbo four cylinder, and permanent quattro four wheel drive.