The 2011 Audi A8 is available as a 4-door, 5-seat sedan. Starting at $84,000, the 2011 Audi A8 quattro Long Wheelbase Sedan is powered by a 4.2L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 27-mpg on the highway. The top of the line 2011AudiA8quattro Sedan , priced at $ 78,050 , is powered by a 4.2L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 27-mpg on the highway.