Lots of names and numbers make up many of the cars found in the Ford Mustang production line as well as the aftermarket.  Some are engineers' dreams, others try to stay close to meaning or capability.  Consider the Saleen S281, the Roush P-51, and of course, the Shelby GT500KR.  The cool thing about this Shelby GT500 variant is that its output is known to be near the 500hp mark.  Or is it?

Actually, the Ford Shelby GT500KR, as tested by the staff of 5.0 Mustang & Super Fords magazine, produces more than 500 horsepower on the dyno.  They took delivery of the blown snake and headed straight to the computerized treadmill only to be surprised by the fact the GT50KR Mustang produced 509hp and about 468 lb-ft of torque at the rear wheels.

If we assume a 15% driveline saturation rate for horsepower loss from the flywheel, this would lead us to assume an actual power rating of almost 590hp & 550 lb-ft of torque!  This is notably higher than what Ford claims to have packaged in this Shelby.

So, does this mean Ford and Shelby should have called the GT500KR "the GT550" instead?  Nah, that would have tainted the comfortable nostalgic tie for the brilliant recipe of marketing success they have enjoyed with the current S197 Ford Mustang.