The 2011 GMC Acadia is available as a 4-door, 7-seat sport utility. Starting at $32,000, the 2011 GMC Acadia SL FWD is powered by a 3.6L , 6 -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 2011GMCAcadiaDenali AWD , priced at $ 45,380 , is powered by a 3.6L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway.