Taking the fastest BMW
6 Series and the fastest Mercedes SL to sunny Cornwall, Chris Harris learns how the M6 and new SL63 match up and discovers how good a job the German automakers have done in combining bucket loads of horsepower and sporting dynamics with GT levels of comfort and luxury. Both cars have in the region of 550 horsepower and similar curb weights, and both are far too quick and powerful for the road. So where do their differences lie? Well, from a styling perspective the general consensus is that the M6 is the better looking car, but the overall performance winner is the SL.