Originally Posted by NISFAN
C63 is such a tail happy car, not fast round a track, too much power.
Although I only have a little wheel time behind the C63 AMG it received quite good press coverage for its very good handling. Its problem is not too much power nor being particularly prone to oversteer. It is just heavy and perhaps a bit under tired. It is generally within 1-2 seconds per minute around a variety of tracks compared to the M3. In most cases that is more of a drivers race than a race among the cars themselves. So yes the M3 is generally faster on a track with less power but more importantly it has a better power to weight. And just like in a straight line, power to weight is the single best simple (one number) predictor of lap times.
Have a look here
for some lap time comparisons.