The other Mercedes GL. The preposterous one. With a price tag and power output to rival the Porsche Cayenne Turbo and 5.0-litre V8 Range Rover. The GL 63 AMG is the Burj Khalifa version of Mercedes’ seven-seat SUV; as applicable to the UK as an 829-metre skyscraper would be to Hounslow - but fascinating nevertheless.
For £91,715 (some £30k more than the Mercedes GL 350) you get flared wheel arches filled with 21-inch AMG alloys - which in turn are filled with manhole cover-sized AMG brakes - chromed AMG quad tailpipes, AMG sports seats, AMG steering wheel and the roll-nullifying Active Curve Control as standard.
Of course what you is really paying for is the generator of 550bhp and 560lb ft of torque up front. The bi-turbo 5.5-litre V8 might not conjure up quite the same misty-eyed affection as the naturally aspirated 6.3-litre found in the C 63 AMG, but it’s a mighty unit nevertheless, and specifically intended to handle heavier loads in the Mercedes range.
Best to get someone else to start the GL 63; that way you can stand out the back and marvel at the wall of sound emerging from its rear end. Don’t expect passers-by to join you in the AMG appreciation society though – unless you’re actually about to drive the thing it probably seems as anti-social as a rocket-powered bus.
Drunk from inhaling 288g/km of CO2, the car’s party trick – getting 2580kg from a standing start to 62mph in 4.9sec – is pretty much irresistible right from the get go. Like most of its rivals, the GL 63 takes a moment or two to overcome its own inertia, and then surges forward through its first three gears like it were attempting to climb into orbit.
Unlike most of its rivals, this rolling planetary mass must then be slowed significantly before anything as irksome as a corner is attempted. The GL 350’s marginal issue with weight transfer is thoroughly and inevitably worsened, too often leaving the front wheels with no choice but to spear straight ahead as the burden of all that extra tonnage moves forward.
Overtaking is also less fun than you might expect. The GL 63 gets the Speedshift-Plus version of the 7G-Tronic transmission to cope with the extra grunt, but all too often, when an intuitive downshift is required, it proves reluctant to live up to its name. Yet for every attempt it fluffs, you will chicken out of three more; largely due to the paranoia associated with correctly and considerately placing a 150mph minibus in the path of oncoming traffic.
It’s hard to see why you would. The GL 63’s shortcomings (and the UK’s modest dimensions) mean you spend most of your time at speeds well within the GL 350’s capabilities – and even if you prefer your SUVs incredibly fast ’n’ thirsty then the similarly high-priced offerings from Land Rover and Porsche make mincemeat of the GL 63 across the board.
Except in terms of outright acreage. The big AMG remains a proper seven-seater straight out of the box, and if you like the idea of your smallest child slumbering in the second row to the melodic hum of a petrol V8, and aren’t fussed by the notion of preserving their natural resources, then it really is the only powerhouse in town.
Mercedes-Benz GL 63 AMG
Price £91,715; 0-62mph 4.9sec; Top speed 155mph; Economy 23.0mpg (combined); CO2 288g/km; Kerb weight 2580kg; Engine 8-cyls, 5461cc, petrol; Power 550bhp at 5250rpm; Torque 560lb ft at 2000rpm; Gearbox 7-spd automatic