We’ll get straight to it. The C 63’s ride is coarse. The car’s axles are entirely the work of AMG so it’s deliberate – an inevitable by-product of the consistent, communicative, closely controlled handling that Affalterbach considered more important overall.
For the most part its a background uncouthness, but it punctures the calm of the cabin with added bite every time you cross a crumbling edge of asphalt or a slightly sunken drain. The suspension’s clunks and thumps get quite percussive over cat’s eyes.
It’s more like rawness than crudeness, though, and it’ll either bother you or it won’t. For one tester, it was an acceptable trade-off for the way the C 63 handles; for another, it would have been enough to cost Mercedes-AMG a sale. No prizes for guessing which of the two spent longer at the wheel.
The C 63’s handling proved less divisive. Although it’s neither as grippy nor as fast around MIRA’s Dunlop circuit as a BMW M4, the car acquitted itself with the greater conviction of the two on the road thanks to weighty, feelsome, trustworthy steering and a sweeter balance of grip at lower speeds.
Body control is firm; not brilliantly damped, but with enough suppleness to deal with a testing surface, if you leave the suspension set to Comfort mode.
Mercedes-AMG is evidently powerless to add much subtlety to Daimler’s stock stability control system, but turn it off and you can enliven the C 63’s directional responses with your right foot on demand – and do so with confidence, too, because the car is controllable and benign in its every response.
You have to go a lot faster and harder than you would on the road to become aware of what separates the car from a BMW M3 or M4 in objective terms. Ultimately, it’s grip. On 19in wheels and Michelin Pilot Supersport tyres, the BMW clings to a circuit harder than the heavier C 63 does on its Continental-shod 18s.
But at the limit of adhesion, the AMG almost always runs out of grip up front first, which makes it more forgiving than the BMW when push comes to shove.