The 2015 BMW 550 is available as a 4-door, 5-seat sedan. Starting at $64,900, the 2015 BMW 550 RWD is powered by a 4.4L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 25-mpg on the highway. The top of the line 2015BMW550AWD , priced at $ 67,200 , is powered by a 4.4L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 25-mpg on the highway.