Car and Driver test drives and compares the 2015 BMW X6 M and the 2016 Mercedes-AMG GLE63 S Coupe. The two super sporty SUV coupes are arguably the best in the segment and provide driving dynamics unseen in a Sports Activity Vehicle. The BMW X6 M is a massive 567 horsepower monster, which makes its power from a 4.4 liter twin-turbocharged V8 engine. That engine, or Atom Bomb, is mated to an eight-speed ZF transmission and powers all four wheels, via BMW’s xDrive. This gives the X6 M a 0-60 mph time of 4.0 seconds, making it one of the fastest BMWs on the market and only about a tenth shy of the famous BMW M3.
