Bottom line.... Crank HP as reported by the manufacturer is basically whatever they want to market. For whatever reason, Chrysler decided that 330 was the number that they wanted to put on their marketing material. As far as the differences between the 2 cars, I have raced an SLK32 through a couple of stages of modifications where we have both had the same mods done, and the end result so far has been that we are always within an tenth of each other.

There has been no magical de-tuning of the SRT engine, and the SLK is not a 19HP more powerful car.