BMW's largest SUV comes standard with a turbocharged six-cylinder engine that delivers 375 horsepower. For extra performance, the M60i xDrive model makes good use of a 523-horsepower twin-turbo V8. Want even more power? The exclusive XB7, developed by German tuner Alpina, is still being sold in Canada, boosting output to 631 horsepower and cutting the 0-100 km/h acceleration time to just 4.2 seconds. Not bad for a 2,700 kg SUV!