The 2017 BMW X4 is a 4-door, 5-seat Sport Utility, available in 2 trims, ranging from the xDrive28i to the M40i. Upon introduction, the $45,550 xDrive28i is equipped with a standard 2.0L, 4-cylinder, engine that achieves 20-mpg in the city and 28-mpg on the highway. an Automatic transmission is standard. The $58,100 M40i is equipped with a standard 3.0L, 6-cylinder, engine that achieves 19-mpg in the city and 26-mpg on the highway. an Automatic transmission is standard.