The 2016 Audi S4 is available as a 4-door, 5-seat sedan. Starting at $49,200, the 2016 Audi S4 (M6) is powered by a 3.0L , 6 -cylinder engine mated to a manual transmission that returns an EPA estimated 17-mpg in the city and 26-mpg on the highway. The top of the line 2016AudiS4(S tronic) , priced at $ 50,200 , is powered by a 3.0L , 6 - cylinder engine that returns an EPA estimated 18-mpg in the city and 28-mpg on the highway.