Starting with the 4.4-liter block from the 540i, BMW's M Division bumped displacement to 5.0 liters with a bore and stroke job. Compression is set at 11:1 (requiring the use of premium fuel, of course) and the cylinder heads are redesigned to offer greater crossflow cooling. Outfitted with the requisite double-VANOS variable valve-timing system, this engine is good for 400 horsepower and 395 ft-lbs.