Mercedes-Benz to launch 911 rival

Mercedes-Benz has shoehorned its hot new twin-turbo V8 engine into an AMG-badged compact sports car to be launched in 2015, Wheels can reveal.

We can confirm that the car – to be called the GT AMG – will be powered by the same, all-new 4.0-litre twin-turbo V8 found in the new four-door C63, where it could produce as much as 430kW of power and 700Nm of torque.

In the lighter AMG sports car, the engine is expected to produce a 0-100km/h dash of less than four seconds.

An even more potent Black Series variant is also on the cards.

Captured by our spy photographer during cold-weather testing overseas, the car shows styling cues inspired by the current SLS supercar, though not the bigger car’s distinctive gullwing doors.

The new ‘baby SLS’ will be a price competitor for the Porsche 911, but will not be as hardcore as its iconic rear-engined rival.

Spotted wearing thinner camouflage than in previous sightings, the prototype’s proportions present like a trimmed-down version of the SLS.

While the GT is clearly influenced by the SLS, it is not a replacement for the flagship coupe.

Mercedes-Benz has confirmed that it will be a standalone model in the range.

Overseas pricing of about €110,000 ($A168,000) for the GT will directly challenge the latest 911 Carrera S, which sells for €105,173 ($A161,000) in Europe.

The bi-turbo AMG V8 is essentially two A45 2.0-litre turbo four-cylinder engines mated together. It retains the same 90mm bore and 7mm cylinder wall thickness.