In the same way that the Mercedes-Benz S-class is the flag bearer for the Mercedes range, the S63 is the pinnacle of that luxurious model line. It retains the kit you’ll find on ‘lesser’ S-class models, but turns up the dial with that stunning, hand-built 5.5-litre twin-turbo V8.
That heart develops 577bhp at 5500rpm, just 1000rpm shy of its redline, while peak twist is 644lb ft, which arrives at 2250rpm and plateaus until 3750rpm. It's good for a 4.4sec 0-62mph time and a top speed limited to 155mph (or 186mph as part of the £2760 AMG Driver's Package, which also includes driver training).
But as good as that 5.5-litre V8 is, what actually dominates the car is the sense of money-no-object opulence. Mercedes has left virtually no stone unturned in its pursuit of ultimate luxury. Almost every feature is electrically powered, double-glazed or internet-connected. Most of the facilities are operated via a 12.3in colour screen.
If anything, rear passengers are served even better, with enormous legroom afforded by the long-wheelbase-only chassis configuration. The huge range of options includes a pair of individual seats – a £5000 extra.
Out on the road, one of the impressive aspects of the S63 is its Magic Ride Control, which uses a camera to scan the road ahead to prime the adaptive suspension for the optimum ride. The system, which is standard, works intuitively and really does iron out most undulations, but high-frequency scars can still be felt.
You can deactivate it by switching to Sport mode, and if you’re looking to really dial performance up a notch, you’ll want to. With the full potential unleashed, you can enjoy masses of grip along with the restrained growl from that 577bhp V8.
At speed the S63 feels far narrower than its 2.1m girth suggests, and once you overcome the initial over-assistance, the steering allows you to put enough faith in it to exploit the AMG-specific chassis setup.
It feels more planted at high speed than a Jaguar XJR, thanks in part to a 100kg weight loss over its predecessor, but the Jaguar still shades it in terms of outright fun. The AMG offers the better blend of refinement and engine note; rhythmic at low speed and bellowing with restraint as it approaches the 6500rpm redline. The engine note is delightfully muted, although always there. If you want NASCAR thrills, choose an E63 AMG.
Power is commuted to the rear wheels through a seven-speed Speedshift MCT automatic gearbox. It provides snappy shifts, but – as with the rest of the car – never at the expense of sublime comfort.
The Mercedes S63 AMG wants for nothing, although there is, predictably a myriad pricey options. But it is hard to think of the S63 AMG in pragmatic terms.
The truth is, if you want to travel in unparalleled comfort and refinement, then a cooking S-class, an S350 or an S500 would be slightly better. And an E63 AMG would better serve those looking for traditional super-saloon thrills.
However, the S63 AMG is simply one of the world’s best cars with one of the world’s best performance engines. And it’s hard to argue against it.