The 2021 Audi A8 is available as a 4-door, 5-seat sedan. Starting at $86,500, the 2021 Audi A8 55 is powered by a 3.0LL , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 26-mpg on the highway. The top of the line 2021AudiA860 , priced at $ 98,900 , is powered by a 4.0LL , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 23-mpg on the highway.