The 2009 Audi A6 is available as a 4-door, 5-seat sedan. Starting at $50,100, the 2009 Audi A6 3.0 Premium quattro Sedan is powered by a 3.0LL , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 26-mpg on the highway. The top of the line 2009AudiA64.2 Prestige quattro Sedan , priced at $ 60,950 , is powered by a 4.2LL , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway.