The 2018 Audi A6 is available as a 4-door, 5-seat sedan. Starting at $51,900, the 2018 Audi A6 2.0T Premium quattro Sedan is powered by a 2.0L, 4-cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 31-mpg on the highway. The top of the line 2018 Audi A6 Sport FWD Sedan, priced at $51,200, is powered by a 2.0L, 4-cylinder engine mated to an automatic transmission that returns an EPA estimated 25-mpg in the city and 34-mpg on the highway.