2013 BMW M5 may have more horsepower than reported

With the 2013 BMW M5 finally going on sale in the U.S., we definitely saw this coming. BimmerPost recently got a hold of engine dyno run for the new M5, and is reporting that the car's twin-turbo V8 is "severely" underrated. Officially, the M5's 4.4-liter V8 is rated at 560 horsepower and 500 pound-feet of torque, but the dyno graph reveals numbers at the rear wheels to be 527 hp and 476 lb-ft in completely stock form. While the idea of the engine being underrated is just an assumption, the general rule of thumb is a 15-percent drivetrain loss – if accurate, the new M5's losses would be just six percent.

Autoblog , 2013 BMW M5 may have more horsepower than reported, 2013 BMW M5 may have more horsepower than reported