These cars are pretty close in weight, actually not sure who is lighter since the weight range of the M8 comp is 4,156lbs starting, loaded who knows? Convertible is 4,480lbs. GT500 we know is a porker. Crazy that they are close in weight yet the M8 is AWD running TT. I think Ford needs to step it up with the S650 GT500 and finally go turbos like everybody else.