Joining the six-cylinder diesel G 350 Bluetec in a revamped G-Class range that boasts higher levels of luxury than ever inside, the G 63 is powered by AMG’s latest twin-turbocharged 5.5-litre V8, whose 563bhp and 561lb ft of torque are sufficient to propel this 2.5-tonne brick from 0-62mph in a startling 5.4sec. Although these are startling figures, it is a great shame that the UK misses out on the 4.0-litre V8 and 6.0-litre V12 iterations of the AMG G-Class found elsewhere in the world, something which Mercedes-AMG don't seem keen to rectify for the 2018 edition.
The V8 is mated to an equally modern AMG Speedshift seven-speed automatic transmission with a stop-start function and a choice of three modes.
This powertrain means that while the G 63 is the quickest G-Class in its history, it is also more economical than its thirsty predecessor and emits less CO2 – although figures of 20.5mpg combined and 322g/km hardly qualify the G 63 as being eco-friendly.
While it’s instantly recognisable as the ruggedly rectilinear Geländewagen that has been around for more than three decades, the G 63 can be distinguished from lesser models by a unique radiator grille and front bumper, flared wheel arches, stainless steel running boards, a macho side-exit sports exhaust system and big alloys. It is also the subject of other mental AMG projects, most notably the Mercedes-AMG G 63 6x6.
Inside, the G 63 now features a more modern dashboard with a new instrument cluster and centre console, as well as a more generous standard equipment level than its predecessor. But despite the unashamed luxuriousness of its cabin, the G 63 remains a potential go-anywhere vehicle, featuring three differential locks and a low-range transfer box for serious off-roading.
As for equipment levels there are three choices - the standard G 63 trim, Colour Edition and Edition 463. The normal G 63 comes with all the bravado AMG like to instill on its creations, notably the 20in alloys, chrome quad side exhausts, red brake calipers and stainless steel side sills, while inside gains climate control, a leather upholstery, a Harman & Kardon sound system and Mercede's Comand infotainment system. The Colour Editions merely give buyers the choice of five rather garish colour combinations - Tomato Red, Alien Green, Galactic Beam, Solar Beam and Sunset Beam.
The range-topping Edition 463 model gains numerous additional luxuries including, 21in alloy wheels, stainless steel under engine guard, headlight protectors, rear TV screens and tuner, two-tone leather seats, a heated windscreen and driving aids - blind spot assistance and adaptive cruise control. All of which adds more luxury and rugged toughness to the exterior.
Despite the way it looks on the outside, the G 63 is anything but a utilitarian vehicle on the inside. High-quality leather covers most surfaces, including the cliff face of a dashboard, and it’s even ruched in the door panels. All of the technology you'd expect to find in any other Mercedes-AMG products is present and correct in the G 63 too, including a Comand Online multimedia system with a seven-inch colour screen perched in the middle of the dash.
Most of the switchgear is familiar Mercedes fare, too – the exceptions being the trio of diff lock buttons high up on the centre console and a low-range selector button lower down. The lofty driving position is quite upright, but it’s very comfortable and roomy up front (although rear legroom isn't exactly generous); you're a lot less likely to crack your elbow against the door than in a Land Rover Defender.
That comfort continues when the car is rolling. Despite its old-school rigid axles, the G 63’s ride is compliant and reasonably well controlled and refinement is commendable for this type of vehicle.
There’s a fair bit of body roll in corners and the quaint old recirculating ball steering is low-geared enough to keep the driver quite busy at times, but in general the G 63 is better mannered than you might expect, albeit no Porsche Cayenne or Bentley Bentayga. And unlike the gargantuan seven-seat GLS, the G-Class isn’t so wide that feels out of place on an average British road.
One source of noise that is always welcome, of course, is that big twin-turbo V8 and the bellow that emerges from the naughty side-exit exhausts whenever you stir the throttle.
Once you’ve overcome a moment of initial inertia, the G 63 accelerates with the same inexorable force as a Bentley. Put it this way: its swollen performance is more than adequate for a vehicle like this, and easily accessed. You can even change gears manually via paddle shifters if you want.
Objectively, you’d have to say that paying £133,000 or more for a vehicle like this is completely bonkers; any number of other, more modern luxury SUVs will do a better job for less money, namely the Range Rover Sport SVR, Audi SQ7 or Porsche Cayenne Turbo. But subjectively, the appeal of its thumping V8 performance and its ‘old on the outside, new on the inside’ design is as clear as that of a contemporary apartment in a converted warehouse.