It’s hard to rationalise the Mercedes-AMG G63 4x4². The people at Mercedes call it the ‘most G-Class ever,’ which means it’s a combination of two extremes: the ridiculous performance of the G63 AMG with the staggering off-road ability that the 4x4² element brings to the mix. That 4x4² (pronounced ‘4x4 squared’) badge brings portal axles, which means there’s a set of gears in the wheel hub that elevates the ride height and creates space for 22-inch wheels shod with suitably huge off-road tyres.
Mixed with the G-Class’s already boxy looks, the result is the sort of Tonka toy monster truck that makes kids go giddy – and us, too. It’s so wrong, but so right at the same time. We’re struggling to consider a genuine reason for buying it, other than perhaps to get to your county retreat, when a hurricane has toppled nearby bridges and grounded your helicopter. You’d be in that helicopter owner category, too, because the G63 4x4² price puts it in the big league – somewhere between £250,000-£300,000 depending on how much you personalise it.
Portal Axles and Bulletproof Engineering
What does that sizeable chunk of money buy? Well, it’s all familiar Mercedes-AMG G63, with the addition of those portal axles to create the ultimate off-roader. The the G63 4x4² is the fourth G-Class to feature portal axles, but it’s the first to do so in the guise of the current model, which has been built since 2018. The previous G-Class was offered as a mad G63 AMG 6x6 (a six-wheeler with six-wheel drive), the G500 4x4², and even as a Mercedes-Maybach in the form of the V12-powered G650 Landaulet, back in 2013, 2015 and 2017 respectively. While Mercedes-AMG has moved on somewhat in relation to its position on electrification and decarbonisation, evidently that memo was lost enroute to the G-Class’s home in Graz, Austria.
Actually, that’s a little unfair, because the G-Class has adopted battery power and a slightly more environmental stance. On the same day we drove this mad thing, we also experienced the EQG prototype, its existence perhaps in some way offsetting the G63 4x4².
Its direct predecessor came about as a kind of last hurrah for the outgoing G-Class, something the engineering team dreamt up for a bit of laugh. The intention with the G500 4x4² was to sell around 150, in the end it sold over 2,100. The demand and the business case existed, and potential sales numbers meant that, this time, the engineers had more than a mere skunkworks budget to build it.
The Most Powerful V8 of Any G-Class
That predecessor made do with the standard G500’s V8 engine, a still potent biturbo unit, but the thinking with the G63 4x4² was go big or go home, hence it uses the engine from the madcap AMG biturbo model. With 577bhp, it’s the most powerful V8 ever fitted to the current G-Class, and is mated to a slick nine-speed automatic gearbox with all-wheel drive. The portal axles were not simply hauled off the parts shelf, either; Mercedes engineered new helical-geared ones to remove the meshing gear whine that blighted the G63 4x4²’s predecessor.
All that adds more weight, but even so, that V8 has enough thrust to hurl this most unlikely of performance cars at the horizon in an experience that feels like you’re shooting your house out of a cannon. It’s a very posh house, too, because the G-Class’s interior is as high-class and as high-quality as they come. It reaches 62mph in just 5.0 seconds, which is a scant 0.5 seconds slower than its lower G63 relation, and sounds magnificent when you wring out that 4.0-litre biturbo V8 with its side-exit exhaust pipes. If anything it feels even faster than that, because you’re sat so high, and the rear squats slightly when you poke the accelerator.
Big, but Agile
This latest monster SUV from AMG is even wider the the previous model, which goes some way to counter the obviously higher centre of gravity, and means it actually corners with surprising agility. The steering helps here; in no small part because the steering wheel actually feels like it’s connected to the front wheels.
It’s huge fun, and the hilarity of hustling something so big, yet so surprisingly capable underlines the work that Mercedes-AMG has put into it, but you do feel the cautious hand of the assistance systems maintaining your line in bends if you get a little bit carried away. Despite the absurdity of it all, the G63 4x4² actually lives up to its AMG billing.
Unstoppable Off-Road
It gets even more interesting off-road. No previous G-Class has ever been phased by rough terrain, and the G63 4x4² only builds on that. That’s most noticeable in relation to the speed you can carry; the portal axles create a huge ground clearance of 351mm (113mm greater than a regular G63) so it makes light work of rough surfaces. The giant, 22-inch alloy wheels with Pirelli Scorpion 325/55 R22 tyres, help enormously, rolling over topography with authority, finding grip and traction everywhere. The extended width, covered by carbon-fibre wheel arch extensions, means the new Mercedes-AMG G63 4x4² straddles the tracks left by other vehicles off-road and simply carves its own path.
It conquers inclines as though they’re non-existent, descends with aplomb, and that additional ground clearance makes for a high wading depth, which is handy if you list crossing rivers among your requirements and don’t want to buy a boat.
It genuinely seems unstoppable, and the height is part of that, but so are the regular G-Class’s multiple locking differentials, the huge axle articulation from the long-travel suspension, and the series of off-road driving modes. There are cameras to help too, one of which allows you to see what’s in front of you, which is particularly useful for scaring yourself before precipitous descents.
There’s also a rear camera (displayed in the rear-view mirror), which is particularly necessary due to the gargantuan spare wheel on the back – it's so heavy that Mercedes-Benz engineers had to strengthen the rear pillar to hold it.
Verdict
Use all the G63 4x4²'s power, and it feels like it’ll stop the world turning, in every sense; it hoses fuel into single-figure miles per gallon, and as a purchase is going to be difficult to justify. Yet for the engineering achievement it represents, this car is magnificent all the same.
Everything is outlandish, oversized, and unbreakable, from the roof-mounted LED lightbar that the Mercedes-AMG people say turns night into day (we’ll take their word for that, having only driven it in daylight) to the optional roof rack, which requires engineers to flash the ESP settings to account for its effect on the centre of gravity. Nobody needs a car like this, but we can imagine plenty will want one.
Fact File
Mercedes-AMG G63 4x4²
Price: Approx £250,000-£300,000
Fuel type: Petrol
Powertrain: 4.0-litre bi-turbo V8
Power: 577bhp
Torque: 626lb ft
0-62mph: 5.0 seconds
MPG: Don't ask
Verdict: A hypercar for off-road enthusiasts, not to mention an engineering marvel.
