Even though a car like the new Viper is not just about the numbers, there is no denying that performance figures do matter, at least for bragging rights. So after testing the SRT Viper’s performance on the track, the guys at Edmunds strapped it to a dyno machine to see how many of the car’s 640 horses actually make it to the rear wheels.

Talk about drivetrain loss. The Viper makes 558 horsepower at the rear wheels. A few weeks ago Motor Trend got hold of a new Viper and proved that it is actually slower around the Laguna Seca than the Corvette ZR1.

So the Viper is not likely to win any Top Trumps competition. But in terms of driving fun, and how it makes you feel, this big beast is in a class of its own.