The SL 63 sits on an aluminium-intensive chassis that gets a uniquely calibrated version of the advanced Active Body Control system offered on the standard SL. Ride height varies according to the driving mode and speed, while pitch and roll are exceptionally well suppressed, even on wildly undulating roads and during all-out cornering. Begin pushing and you discover plenty of front-end bite, and the rear, which has a locking diff a, is remarkably well planted.
The overall limits of adhesion are extremely high – helped, no doubt, by track widths that are up a significant 50mm at the front and 52mm at the rear over the old SL 63’s and a wheel and tyre combo (with the Performance Package) that sites 255/35-profile rubber on 19-inch wheels up front and 285/30-profile hoops on 20-inch rims at the back. With the AMG mode engaged, the recalibrated ESP system also allows you to edge up to the point of breakaway without any premature electronic intervention.
Still, a question mark hovers over the steering. The electro-mechanical system is linear in its actions and extremely direct, offering whipcrack turn-in characteristics. But it fails to weight up with any meaningful resistance in the first quarter turn of lock, even at higher speeds. There’s not much in the way of feedback, either.
AMG development boss Tobias Moers says it is all a matter of tyres, suggesting that the Michelin Pilot Sport 3s of our test car offer the best grip but lack the delicacy of the other choice that will be offered to buyers, Continental Contact Sports.
Inside, the SL 63 is a study in quality. It’s just a pity that the controls of the centre console are set so far back – the result of Mercedes-Benz insisting on the inclusion of two large cupholders in the forward section. So practicality wins out over ergonomics, then. And despite a low-set seat, the driving position is not perfect. Elbow-space is at a premium, allowing it to foul the high-set centre console during push-on driving, which means raising the seat higher than you would like.
As for the standard equipment, well both get the same tech as the regular SL's - including dual-zone climate control, LED headlights, parking sensors and reversing camera, and Mercedes' Comand infotainment system. The SL 63 adds AMG-developed bodykit, suspension, limited slip diff, seven-speed race engineered gearbox, heated sports seats and steering wheel, while the SL 65 gains cooled front seats, Bang & Olufsen stereo system and a driving assistance pack - which includes adaptive cruise control, active emergency braking, lane keep assist and blind spot warning.