The Audi S4 is the high performance variant of Audi's compact executive car A4
B5 Audi S4 biturbo quattro
The original Audi S4
Audi S4 Quattro was a performance-oriented version of Audi's 100 saloon/sedan
A more powerful internal combustion engine
S4 variants have had longitudinally oriented front-mounted engines
Super Turbo Engine Audi S4 Quattro