What's all this about?

Oh, just the piffling matter of the second-ever bespoke AMG product - the Mercedes-AMG GT, an Affalterbach in-house creation that isn't based on a series production Mercedes.

So this is the successor to the mighty SLS AMG, right?

Er, no. AMG boss Tobias Moers is keen to say that this is a rival for the Porsche 911 and Jaguar F-Type. Therefore, it's more of a sports car rather than the fire-breathing supercar the SLS AMG was, which stomped about the sort of territory occupied by Audi's R8, Aston Martin's Vanquish and even the McLaren 12C. Although classifying the GT as a sports car is a bit disingenuous; anything that can get from 0-62mph in either 4.0- or 3.8 seconds, and run on to 189- or 193mph, is pretty damned rapid in our book.

Eh? Why are there two sets of performance data?

Because there will be two AMG GT models, the normal GT and the GT S. Both will be powered by the monstrous M178 4.0-litre V8 biturbo engine - which sounds absolutely bloody fantastic, by the way - but with 462hp and 600Nm for the entry-level version, and a colossal 510hp and 650Nm for the S.

I bet they're good on fuel, then...

Well, in that modern car alchemy that allows both epic performance figures but also scarcely believable parsimony, AMG is saying the GT will hit 30.1mpg combined in S guise and 30.4mpg otherwise, with CO₂ pegged at 219- and 216g/km respectively.

How does it achieve this arcane magic?

It's light. Extensive use of aluminium and even magnesium in its structure means the AMG GT is just 1,540kg and has a weight distribution of 47:53 per cent front-to-rear. The roof structure, for example, is lighter by 18kg than it would have been had it been made of steel, while the entire body-in-white weighs a scant 231kg. That means a lower centre-of-gravity, while a magnesium bar in its schnozz means the GT should be keen to turn in, too.

What's it like within?

It's a pure two-seater, but it's suitably opulent, with an 8.4-inch touchscreen dominating proceedings and a two-tiered dash providing elegant form. Also, it has a much bigger boot than the SLS AMG, claimed to be around 350 litres (big enough for two golf bags), thanks to a proper fastback rear aperture.

So is it any good?

We've not driven it yet but it looks absolutely sublime in the metal and it also sounds pretty meaty, even when it's just rumbling around at near-idle. If it can bring some of the SLS's grandstanding theatre to proceedings with a sharper, more adjustable chassis, Stuttgart and Coventry should be feeling more than a mite concerned. The Mercedes-AMG GT will hit UK shores in April 2015, with prices announced next month.