Basic principle of speed is how much drag or weight is affecting it. Mercedes is more concern on the safety of the car than speed and safety means more materials are being added to the car. The luxury we enjoyed also adds up to it's weight making our crossfires much more heavier and these features are not found in the SRT-4 because it's just a Dodge.

If you do the opposite like putting all what our crossfires have to the SRT-4...I think it'll be running slower too.