I was always a big fan of the CLS 55’s thumping nature, but there’s something about the CLS 63’s ability to rev higher that ultimately makes it more satisfying.
In straight line terms there’s not much between them, the CLS 63 pipping the CLS 55 from 0-62mph with a claimed 4.5sec versus 4.7sec: the 500bhp 5.0-litre V10 powered BMW M5 now has a much more focused rival to face up to.
One upside of the CLS 63’s lower torque rating (and surely the reason why it’s able to outrun its predecessor) is that it receives Mercedes-Benz’s excellent 7G-Tronic seven-speed automatic rather than the CLS 55’s older five-speed ‘box. No conventional torque converter-equipped automatic operates with such apparent efficiency on a wide open throttle.
Try it and you can see why AMG insists its loyal customers don’t ask for anything else. It offers three modes – comfort, sport and manual, the latter of which sees it hold on to each gear, refusing to change up even at maximum revs.
The modifications to the chassis are rather less dramatic than those concentrated under the bonnet. The steering, for a start, is spot on. There’s none of the lightness and vague off-centre feel that affects other Mercedes. Instead, you get a meaty action and a lovely linear action in the first quarter turn of lock.
On the optional 19-inch wheels and 255/35 (front) and 285/30 rubber worn by our car there is massive purchase, the kind that allows you to take big liberties. A spot of tail-out action is there for the taking with the ESP disengaged. The CLS 63’s rear-wheel drive chassis more than meets the demands placed on it by its mighty new engine.
Despite the low profile rubber, the ride quality is purposely firm but never crashy. Granted, we’ve only driven it on smooth German roads, but the ability of the CLS 63’s air suspension to soak up ruts and ridges is something that marks it out as one of the world’s most accomplished performance saloons – expect that Mercedes would rather that we refer to it as a coupe, of course.
The troubled electro-hydraulic Sensotronic stoppers used by the CLS 55 have been replaced by new hydraulic units with 360mm (front) and 340mm (rear) discs. The pedal has a more progressive action and more feel through its travel – all of which provides the CLS 63 with huge levels of retardation.
Should I buy one?
Initial impressions are that the CLS 63 perhaps falls short of delivering the same sort of crushing performance dished out by its predecessor. But stick with it and you discover it is in fact a much more rounded car: one that’s better to drive, faster where it matters most, more forgiving at the limit and brilliantly supple. It replaces it with a level of finesse you just didn’t get before. In the end, it’s this particular quality that really sets it apart.