Is the F10 M5 Underrated from Factory?

They’re test run says the F10 M5 is making 527hp at the wheels. That number is strange for a reasons. Typically, horsepower is measured at the crank and loses about 15% by the time it gets to the wheels. We say typically, because if this is true, that means the the M5’s twin-turbo V8 is making somewhere around 610hp.  Mind you, the car is rated at 560 hp. That represents a 50hp difference between what they say, and what it actually makes.

It could just be that their dyno is incorrect, or the car is adjusting timing for higher octane fuel (E85 maybe?), or it could just be straight up magic. Still, it might just be that M5 is more powerful than it’s numbers suggest. They wouldn’t be the first ones to do so, and we don’t suspect they’ll be the last.