Mercedes-AMG GT 63 4-door Coupé 2018 first drive

Next, to the local stiffening they’ve carried out to the GT 4-Door’s body-in-white; and there’s plenty of it, mostly between and around the car’s suspension turrets. And then they’ll flag up the four-wheel steering system they’ve fitted here, only thus far applied elsewhere to the GT sports car.

“For me, it’s actually the way the car’s chassis and drivetrain systems interact (4Matic+ four-wheel drive, e-diff, adaptive air suspension, four-wheel steering and electronic stability control) that puts the GT 4-Door on a different level to our performance saloons and coupés,” explains Demian Schaffert, one of AMG’s Driving Dynamics managers (who also says he’s personally done a sub-7min 30sec Nordschleife lap in this car, which is going some).

“The way everything’s networked together is something special; you can tailor the car’s handling precisely as you like it, to your own preference from everything from steering weight and exhaust noise to high-speed stability, cornering stance, throttle adjustability and more. Trust me, this isn’t possible in an E63.” Don’t worry, Demi: we’ll trust anyone who can make two tonnes of metal lap the ’Ring in less than seven-and-a-half minutes. That’s Carrera GT-level pace.

What really matters about this car isn’t anything to do with Nürburgring lap times, of course. All that anyone getting out of an AMG GT will care about is how much easier the GT 4-Door is use. Can grown adults sit in the back seats? Is the boot a proper size? Can I get in and out of the front without slipping a disc? And can it handle a slightly icy roundabout at midnight in February, on my way home from wherever, without frightening me halfway into a Porsche 911 Turbo?

The answers there are all entirely positive. AMG supremo Tobias Moers likes to make bold claims about his cars, but when he says the GT 4-Door has a breath of ability that he thinks is unmatched among four-seater sporting GTs, he is to be believed. Stick the suspension in ‘comfort’ mode and the GT 4-Door rides very nicely but for a bit of low-speed damping bristle. The gearbox is smooth and slick. The sports seats are bolstered – more so than in most performance saloons – but they’re comfy and accommodating. The rear cabin’s big enough for six-foot adults to be pretty at ease in, and the boot’s bigger than you get on most family hatchbacks. It may have more torque than most supercars but this car needn’t come close to scaring you on the road. And, more importantly, it needn’t worry, frustrate, discourage or annoy you with any high-strung histrionics either – which you couldn’t say of an AMG GT.

But that’s all to do with only one end of the car’s broad spectrum of ability – and to explore the other, access to a venue such as Austin’s Circuit of the Americas, where Messrs Hamilton, Vettel, Ricciardo et al will all be headed next month, is a handy thing to have. On the road, because the GT 4-Door is a more dynamically rounded, civilised thing than a GT sports car, it is perhaps a little less exciting than its two-seater ‘relation’. But you’d take that, and you certainly wouldn’t complain: because when you go looking for real excitement in the GT 4-Door, in the most appropriate sort of place, you’ll find it in abundance.

This is a big car with the agility, balance, body control and indulgent adjustability of something much smaller and lighter – but, as we know, it’s not alone in being like that. In terms of outright lateral grip and braking power, it’s great – but not really in a different ballpark than, say, a BMW M5 or a Porsche Panamera Turbo. But even when you’re driving the GT 4-Door flat out and you’re making it corner more neatly and quickly than a two-tonner ought to be able, its dynamic voodoo is perfectly hidden.

There must be all sorts of things going on all the four corners of this car to make it handle so sweetly mid-corner, and to stop from high-speed with such stability: sizeable changes in suspension setting, e-diff setting and drive torque distribution, and polar switching of the car’s four-wheel steering logic. They’re things that AMG’s rivals either have to allow you to perceive, or to mask with over-assistance.