The 2006 Audi A8 is available as a 4-door, 5-seat sedan. Starting at $68,130, the 2006 Audi A8 Quattro 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 24-mpg on the highway. The top of the line 2006AudiA8W12 Quattro Long Wheelbase Sedan , priced at $ 118,190 , is powered by a 6.0L , 0 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway.