[Bhobbs]

Originally Posted by SUMMIT WHITE SS

That is actually not correct. GM has the SAE testing done with a third party, but GM chooses the rating. We use various SAE power certifications at my job and I am very familiar how they work. GM can have a engine SAE certified, and release a slightly different number, and still be within SAE tolerances. It's common to rate slightly under to give a little buffer. A good example of this was the last gen Viper. It was rated at 510 hp, but was certified at 512. They can also choose to go the other way. Like that Viper could have been rated at 517 and still fell within SAE tolerances. Depending on the Jxxx rating, variances can range from 1-2.5%. But, under rating isn't usually frowned upon as long as it's reasonable, as advertising less and getting more isn't a bad thing. But if you want to keep your SAE certification, you can't over rate more then the 1-2.5% that the Jxxx certification allows.

Fair enough but my point was SAE wouldn't rate the car at 750 hp and GM rate it at 455. The SS was around 458 and GM says 455. Three hp isn't a major difference and within tolerance so it may be the actual rating.