It's called underrating.
If you’re in the market for a supercar but need something with four doors, there are a few possibilities, among them the BMW M5 Competition. Powered by a 4.4-liter twin-turbo V8 with twin-scroll turbochargers, it produces a total of 617 hp at the crankshaft and 553 lb-ft of torque. Oh, and it weighs over 4,200 pounds. Not exactly lightweight.
As Car and Driver has just discovered, BMW’s performance specs are not precise. C&D took an M5 Competition to the dyno at Livernois Motorsports and Engineering in Dearborn Heights, Michigan for a little test. The goal, quite obviously, was to see how much power the super sedan truly has. Running the car in sixth gear to avoid torque multiplication by the eight-speed automatic transmission, the dyno results are both surprising and very impressive.
Total peak output came to 617 hp and 606 lb-ft at the wheels. The latter is nearly 10 percent more than the BMW factory claims. So just imagine all of that power to all four wheels. That’s pretty incredible and it’s no wonder the M5 Competition makes the sprint to 60 mph in only three seconds. So what have we learned from this?
Basically, BMW’s official figures are conservative and we wouldn’t be surprised if the automaker admitted it deliberately underrated the M5 Competition. This wouldn’t be the first time an automaker has done this and certainly won’t be the last.
To put into clearer perspective just how powerful the M5 Competition really is, the Ford GT pumps out 647 hp and 550 lb-ft of torque. While the GT weighs less (3,381 pounds), it just goes to show the length BMW M went to make the M5 a bona fide supercar with a pair of rear doors. In fact, C&D’s own track tests previously revealed the nearly two-ton M5 Competition was nearly as quick as the GT on the quarter-mile run. Now we know why.