The 2016 Audi S4 is a 4-door, 5-seat Sedan, available in 2 trims, ranging from the (M6) to the (S tronic). Upon introduction, the $49,200 (M6) is equipped with a standard 3.0L, 6-cylinder, engine that achieves 17-mpg in the city and 26-mpg on the highway. a Manual transmission is standard. The $50,200 (S tronic) is equipped with a standard 3.0L, 6-cylinder, engine that achieves 18-mpg in the city and 28-mpg on the highway. an Automatic transmission is standard.