Review: Mercedes-Benz S63 AMG

You won’t find ‘Race Start’ on the new Mercedes-Benz S63 AMG. The launch-control technology that helps make the smaller E63 AMG the fastest accelerating sedan in Wheels’ history is ignored in the still supercar-fast S63. Don’t underestimate the significance of this decision in helping to define AMG’s version of the new S-Class.

The reality is, this is not a car for track days. The emotional and aural drama of lesser AMGs, like the E63, has been replaced by cultured refinement and unmatched levels of comfort and space that isolate the S63 from the road, and almost everything else on the planet.

Which is not to say that the bi-turbo 430kW/900Nm (up 100Nm over the E63) 5.5-litre V8 is somehow tranquil in terms of performance. Hardly. This huge 5.2-metre long (that’s the short wheelbase, the long is 5.3m), 1970kg limousine belts to 100km/h in 4.4 seconds. Order the ‘driver’s pack’ and, with the 250km/h speed limiter removed, the Vmax is lifted to 300km/h (in testing, AMG says it topped 315km/h).

Yet the S63 can be even quicker. In all-wheel-drive form (via a 33/67 percent front-to-rear split), the time drops to only 4.0sec – 0.3sec slower than the E63 using Race Start. But AWD is denied us because the steering column can’t fit around the shaft that carries drive to the front axles, located on the right of the engine. AMG promises this is the last time we’ll be denied the traction benefits of AWD – from next year’s all-new C-Class, Mercedes’ 4Matic system will be offered globally.

Unlike other versions of the S-Class, which retain Merc’s super-smooth 7G-Tronic torque- converter automatic, the S63 uses the MCT auto, which combines a hydraulically actuated clutch with planetary gears to give quicker reactions. Gear changes may be swifter, but they are also less fluent and occasionally, especially at low speeds on light throttle openings, just a touch erratic, with the throttle difficult to modulate for ultra-smooth driving.

Our S63s also get Merc’s ‘Magic Body Control’ as standard, the system that uses stereoscopic cameras to ‘read’ the road and to adjust dampers accordingly when in comfort mode, but is deactivated in sport. No surprise, then, that with ‘comfort’ selected, the S63 virtually matches the regular S-Class in terms of refinement and soothing luxury.

Tobias Moers, AMG’s new CEO, as well as the former head of development, says AMG began work on the S63 from the beginning of the W222 S-Class project. The S63 gets hard rubber in the bushes, unique front upper control arms and, while the body-in-white is identical, additional front and rear bracing between the sills and the subframes, all to cope with 900Nm of torque.

The S63 also weighs around 100kg less than the outgoing model, thanks to the first lithium-ion battery to be standard in a production car and a carbon spare- wheel well, as well as alloy panels and forged wheels.

If the S63 is short on drama and big on impact, and its character less redline-probing, that’s because AMG wanted to broaden its appeal as a supremely talented powerhouse limousine.

At first, the S63 feels massive – a car most at ease in the outside lane of autobahns. After more wheel time, you learn it hides that bulk well, even on really tight roads. The rear-drive car’s steering is lighter and more natural in feel than the 4Matic, but loses out on wet roads when the mighty engine, which pulls relentlessly from just above idle, can send the rear wheels into a frenzy. At the top end, the mighty V8 automatically changes up in drive just above 6000rpm and it’s all too easy to accidentally hit the soft 6300rpm limiter if you insist upon changing gears manually.

Stop the car, hold the brakes with the left foot, turn the gear selector to manual, select Sport and floor the accelerator. The 4Matic S63 momentarily chirps its rear wheels and then simply lunges forward, the big limo seemingly defying gravity in the way it hurls to the horizon, the subtle exhaust bark exactly right, and without the frenzied theatrics of the E63. An adaptive exhaust system keeps its valves shut on start-up and, for most of the time, the car operates in Comfort. As expected, Sport introduces more induction and exhaust noise, especially with a heavy right foot.

Try the same trick on a wet road in the rear-drive S63 and the back end steps out, the rear wheels spinning furiously. The split-second up-shift to second brings more wheelspin and a rear-end twitch that’s repeated on the shift to third, the speedo needle bobbing around 130km/h. It’s here, on slippery surfaces, that the loss of traction and the four-tenths of a second advantage of the 4Matic in acceleration to 100km/h are immediately palpable.

There is something faintly ridiculous in the way the S63 flashes to 200km/h in a cocoon of well-mannered opulence. No car in my experience has ever concealed its speed as well. The S63 offers huge 420mm ceramic brakes as an option, though the standard composite discs are brilliant – a short, linear pedal travel and seemingly fade resistant, at least on the road.

Inside, it’s obvious this is the more sporting S-Class: the sports seats offer massive lateral support and superb comfort, the cabin is littered with AMG logos, while the two-spoke steering wheel introduces a thicker rim and larger shift paddles.

If the S63 lacks the tangible excitement of the E63, that’s fine. This $400,000 slice of peerless Mercedes can be brutally effective. But that is to miss the point: by crawling as well as it bahnstorms, the S63 proves its supremacy by being better equipped, more classy to sit in and look at, and just as fast as any rivals.

Self-indulgence doesn’t come any better, unless you’re waiting for next year’s S65 AMG, the tweaked V12 S-Class with 475kW, 1000Nm, and even wider tyres.