The 2020 Audi S5 is available as a 2-door, 4-seat coupe. Starting at $51,900, the 2020 Audi S5 quattro Coupe is powered by a 3.0L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 27-mpg on the highway. The top of the line 2020 Audi S5 quattro Sportback, priced at $51,900, is powered by a 3.0L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 27-mpg on the highway.