The GL 500 has the same engine, by name, but the AMG boffins have been up to their usual high standard of psychotic over-engineering with the end game of making big power and big torque without running the risk of big bangs.
As a package, the GL was a bit of a surprise. For starters, it doesn't seem like you're trying to pilot the Ark Royal around, despite it being an enormous 2600kg.
Trying to get around inner-city car parks is a bit of a trial, but this is true of many large seven-seaters. Parallel parks require a bit of effort too, but with parking sensors, cameras and a bit of backing and filling it's achievable. Once you've parked it in a nasty spot for the first time the daunting prospect becomes less of an issue.
Although it is not be the prettiest vehicle that Mercedes has to offer - mostly because of its sheer size and the huge front - there is something quite alluring about it. There's the nicely executed grille, with a blackout background dressed in a couple of thick chrome trim lines that help the three-pointed star "float" on the front.
Another chrome line across the bottom of the front bumper avoids it looking like an extension of the bitumen - very necessary considering the metallic black on the test vehicle gave the impression it was growing out of the road like some giant character in a fantasy flick. At 1.85m high it commands some respect on the road.
On the inside life is pretty sweet indeed, with the high standard Designo leather wrapping the gigantic cocoon AMG seats that can be tweaked until the perfect seating position is found, a very tasteful AMG instrument cluster, and piles of equipment that many will ignore but that converts will soon find themselves unable to live without.
The seats have ventilation, a heating function as well as a massage feature. A drive into the CBD through the demonic post school-holiday traffic was improved markedly with a bit of a backrub and a warm bum.
Seven-seater functionality usually comes with a cold serving of compromise but Mercedes has addressed this in the best way possible. Push the boot button, let it open for you, then flick either back row switch to fold down the seats.
Now for the exciting bit. There's no doubt that 410kW twin-turbo V8 stretched-out SUVs are bit anti-social, and the market for combination family convenience/savage road weapons is quite limited. But the staggering thing is that this drives like a slightly taller S-Class. It has the luxury appointments, it has the engine and, despite its huge dimensions, it's a performer.
The engine delivers 760Nm of torque through the seven-speed auto, which has manual shifting options. For some reason that only Mercedes' power-lusting witchdoctors can explain, it hits 100km/h in a shade under five seconds.
That's in the same ballpark as other AMGs that have their weight problems under control and is extremely impressive. The suspension can be fiddled with by simply pushing a button, offering comfort, sport and very-sport options, and with the Active Curve Control the GL handles itself very well on the open road. This new system locks up the anti-roll bars when cornering at pace, and with the air suspension continually keeping itself sorted the result is a very stable ride. It still has a huge amount of power on tap, and that in itself needs to be respected. But even in backroad bursts from corner to corner it stops quickly and stays flat until you have it pointed straight and are setting it up for the next corner.
The 5.5 is a bit obnoxious with a big roar on start-up and an engine note that leaves nothing to the imagination, without being overbearing and invasive. Personally, I'm a big fan of the old naturally-aspirated 6.3 V8 and its hugely rorty sound and power delivery, but that's best reserved for saloons, coupes and other machines that aren't going to be carting around the whole family.
To get behind the wheel of the GL 63 isn't cheap at $235,900, and keeping it fed will come at a cost too. The factory combined figure is 12.3L/100km, but during our test period it was notching up numbers north of 20L/100km. The GL 500 was a bit less thirsty and there's a diesel version that's bordering on cheap to run.
One thing is for sure, this is a brilliant machine for moving people about - but it's certainly not a soulless "people mover".
The GL63 AMG is a mighty big machine.Pictures / Ted Baghurst