Seeing as we are dredging up comparisons with members of AMG’s extensive back catalogue, here’s another one: this S63’s recorded 0-100mph time of 7.1sec is nearly a second and a half quicker than that of the then £249,500 SL 65 AMG Black Series of 2009, a no-compromises, fire-breathing Mercedes supercar of the first order. If that’s a bit abstract, consider that the 30-70mph time in kickdown is just three-tenths shy of the time recorded by the thunderous, five-star BMW M5 CS, only recently retired. It’s unsurprising that the S63 is an enormously rapid saloon, and it feels so even when you don’t call on its full potential. There’s a palpable depth to its reserves, even if you’re only indulging in a little gentle roll-on acceleration in Comfort mode. The electric element of the powertrain is partly responsible for this, as it gives the big saloon an unusual alertness at all times, yet this never spills over into sensitivity. If you do need to kick down, the gearbox shuffles itself quickly enough, and shortly thereafter you are, in essence, riding a 5.3m rocket, although the S63 disguises road speed eerily well. Gearshifts are normally slickly executed if the powertrain is under reasonable load, and as you ramp up through the modes, of which Sport+ is the most aggressive, the car will even cut ignition to hasten shifts and maintain momentum with torque fill from the electric motor. It’s an effective technique, although with so much torque in play in general, the delivery often has an EV-esque uniformity to it, even if the slightly repressed V8 woofle – both real and manufactured – never lets you forget what’s ahead of you. The delivery is more impressive than it is lovable, though. It’s also not infallible. On more than one occasion our test car elicited driveline shunt, particularly at low speeds, that has absolutely no place in a world-class limousine, red-hot or not. This hybrid driveline is also noisy at times, clicking and clunking in a way that makes the car feel fragile, even if it is just business as usual mechanically. Our final complaint is that the topping of electric torque that sits on a bed of V8 grunt is not always sensitively delivered. The boost provided by the motor comes and goes, with no relation to the shape of the engine’s efforts. The result is fast, sure, but it’s also a bit unsettling.
