Originally Posted by Big Country
Ford released the official horsepower rating of the GT500 at the Detroit Auto Show. 475hp is what they are listing it at. I'm willing to bet on dynos that it will be even higher. The engine in the GT500 is more or less the same engine used in the GT, only a different supercharger. The GT is listed at 550hp, but dynos have shown it to be closer to 600hp.
I thought they had recently changed the "rules" for measuring and reporting horsepower. That's why the new Civic Si is listed at 197 instead of 200. They standardized some things and left less room for manufacturer "lowballing."
I also read, when they did that, that a lot of the US manufacturers had to list their vehicles at higher numbers, while a lot of the asian manufacturers had to lower their listed numbers.