The 2003 BMW 540 is a 4-door, 5-seat Sedan, available in 4 trims, ranging from the i (M6) Sedan to the Base. Upon introduction, the $55,800 i (M6) Sedan is equipped with a standard 4.4L, 8-cylinder, engine that achieves 15-mpg in the city and 23-mpg on the highway. a Manual transmission is standard. The $51,800 Base is equipped with a standard 4.4L, 8-cylinder, engine that achieves 17-mpg in the city and 21-mpg on the highway. an Automatic transmission is standard.