What's all this about?

It's Mercedes-AMG's first-ever practical car, the GT four-door Coupe. Following multiple teases as a concept, it has been revealed to the world at the Geneva Motor Show.

I'm confused. What about the CLS? Or E-Class?

Ah, perhaps we need to clarify the situation. Since Daimler's big badging reorganisation of 2015, there have been three strands to the company with the three-pointed star: Mercedes-Benz, Mercedes-AMG and Mercedes-Maybach. Now, obviously there is overlap between these supposedly disparate concerns, most obviously when Mercedes-AMG takes a series Benz production model - like a C-Class or an E-Class or an S-Class or a GLE, or whatever - and does what it has done since time immemorial: stuff a massive engine up front, beef up the chassis, give it loud and shouty V8 noises. Lovely. However, since being hived off into a standalone concern, Mercedes-AMG has developed two models in its own right.

I think I'm beginning to see where this is going...

Excellent - but allow us, for the avoidance of doubt, to clarify fully. These were the raucous SLS and the current family of two-door coupe and convertible GT sports cars. The difference here being that, while these two shared drivetrains with AMG-ified Benzes, they never use(d) anything less than full AMG motive power - so you don't get diesels, you don't get small four-cylinder engines; you just get high-output, big-capacity units.

And the GT four-door Coupe is the third 'full' Mercedes-AMG?

Indeed so. With four doors, a fastback rear, acres of room in the back and looks that blend the third-gen CLS with the AMG GT, you end up with a glorious big sports coupe that can be used on a day-to-day basis by families. If they've got a lot of money, obviously. But, by crikey, some of the stats for the AMG GT four-door Coupe...

Please do go on.

There's a 53-badged hybrid model first up. Powered by the electrically-augmented 3.0-litre turbocharged V6 petrol engine, its peak outputs of 435hp and 520Nm can be temporarily elevated by the EQ Boost system. The GT 53 Coupe weighs a considerable 1,970kg, but 4Matic all-wheel drive and an AMG Speedshift TCT 9G nine-speed gearbox ensure it can hit 62mph from rest in 4.5 seconds and run on to 177mph. Eco-stats are commendable at 31mpg combined and 209g/km of CO₂ emissions.

What else has the GT four-door Coupe got up its sleeve?

Two V8 models, with and without an S. And the latter rectifies the weird situation whereby, of all the AMG-badged Mercs that use the 4.0-litre 'hot inside V' twin-turbo V8 engine, it's the E 63 S that currently has the most horsepower, rather than the wildcat AMG GT R. However, before we get to the new V8 AMG king, let's do this in order. The Mercedes-AMG GT 63 Coupe has a tremendous amount of punch: 585hp, ably assisted by 800Nm, this grunt channelled to all corners with 4Matic+ and a nine-speed MCT AMG transmission. It tips the scales at 2,025kg and yet can do 193mph flat out and 0-62mph in a searing 3.4 seconds. It returns 25.7mpg and 252g/km CO₂ to boot.

Oof, that IS quick! But what about this S version?

It's the most powerful 4.0-litre V8 yet seen across the whole Mercedes brand, and you can find it in the Mercedes-AMG GT 63 S Coupe. Outputs are hiked 54hp and 100Nm over the 63, to stand at peaks of 639hp and 900Nm. The S gets the same drivetrain as the 63, only there's a Drift Mode in its 4Matic+ programming, and it gains 20kg too, but it'll run 0-62mph in a hypercar-esque 3.2 seconds and hit 197mph flat out. You won't pay a huge penalty in terms of on-paper efficiency, the GT 63 S capable of 25.2mpg and 256g/km CO₂ - and the 'green' advantages of the 585hp car are wiped out if you fit the regular 63 with its biggest optional wheels, as it'll then turn in the same consumption/emissions numbers as the 639hp S.

So many V8 AMGs! Can we just touch on the Coupe's interior?

Yes, it sports the twin 12.3-inch TFT screens known as the Widescreen Cockpit, while we love the two rows of 'black panel' switches flanking the transmission tunnel. Mercedes-AMG says the GT four-door Coupe is built to satisfy punters in the sports car market who are 'looking for a vehicle for day-to-day use but who are unwilling to go without the unparalleled performance of Mercedes-AMG'. Presumably, then, the sort of people who simply will not contemplate, for whatever reason, something as genius as the Mercedes-AMG E 63 Estate...