The 2011 Ford Flex is available as a 4-door, 7-seat sport utility. Starting at $29,355, the 2011 Ford Flex SE FWD is powered by a 3.5L , 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 2011FordFlexTitanium w/EcoBoost AWD , priced at $ 45,520 , is powered by a 3.5L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 21-mpg on the highway.