The 2015 Ford Flex is available as a 4-door, 7-seat sport utility. Starting at $29,100, the 2015 Ford Flex SE FWD is powered by a 3.5L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 25-mpg on the highway. The top of the line 2015FordFlexLimited w/EcoBoost AWD , priced at $ 42,400 , 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 23-mpg on the highway.