The Audi S4 was a series of performance focused variant of the Audi A4. This generation of S4 was based on the B6 Audi A4, and was offered as a sedan, convertible, and 'Avant' station wagon. The B6-based S4 was fitted with a 4.2L V8 engine and was the top of the line variant available for the B6 Audi A4 as no RS4 variant was offered. Production of the S4 (B6) sedan and station wagon lasted until 2004, while the convertible version was built until 2005.