The 2016 BMW Z4 is a 2-door, 2-seat Convertible, available in 3 trims, ranging from the sDrive28i (M6) to the sDrive35is (A7). Upon introduction, the $49,700 sDrive28i (M6) is equipped with a standard 2.0L, 4-cylinder, engine that achieves 22-mpg in the city and 33-mpg on the highway. a Manual transmission is standard. The $66,350 sDrive35is (A7) is equipped with a standard 3.0L, 6-cylinder, engine that achieves 17-mpg in the city and 23-mpg on the highway. an Automatic transmission is standard.