The arrival of the controversial X5 M and X6 M might be confirmation that BMW has dumped every engineering principle that made its M cars so distinctive and consistently good for the last thirty years. Until now, all M cars have had a high-revving, normally aspirated engine, a manual or automated manual gearbox, rear-wheel-drive, and a sedan or sports car shell. You won't find a single one of these qualities in M's latest efforts.
The M versions of the X5 and X6 sport-utes go on sale in the fall, but BMW allowed us to drive prototypes at their winter test center in northern Sweden several months ago. Under their skins, the two trucks are the same: both use an M-massaged version of the twin-turbocharged V-8 and the trick rear differential from the X6 xDrive50i. The 4.4-liter V-8 engine has been boosted from 400 hp and 450 lb-ft of torque to 550 hp and about 500 lb-ft of torque.
Unlike other M cars, there's no delicate balancing of clutch and revs to hinder a clean getaway, and no fiddling with the launch control system, either. Engage 'D' in the regular six-speed automatic transmission, boot the throttle, and the mighty engine slings you forward with a loud, raspy roar - and complete disregard for the behemoths' 4800-pound mass. BMW promises their wundertrucks will be quicker and cheaper than the Mercedes-Benz ML63 AMG and the Porsche Cayenne Turbo.
The xDrive all-wheel-drive system has been reprogrammed to send more torque to the rear axle and keep it there. It lets you indulge in long drifts that an M3 would be proud of. Low-grip surfaces emphasize the precision and delicacy of the steering and brakes.
One engineer slipped - doubtless deliberately - that in testing, the X6 M is as quick around the Nürburgring as an M3. You can be as upset as you like about the inherent absurdity of a 550-hp sport SUV, but it's hard to argue with how good these particular ones are to drive.
Price: $95,000 (est.)
Engine: 4.4-liter turbocharged V-8
Power: 550 hp
Torque: 500 lb-ft
Drive: 4-wheel