The new plug-in hybrid version of the Mercedes-AMG GT is not just the brand's quickest-accelerating road car yet, but also one of the fastest cars in production. 

Arriving just a few months before Porsche is expected to reveal the long-awaited hybrid version of the 911, the GT 63 S E Performance shares its electrified innards with the recently revealed SL hybrid. 

AMG's twin-turbocharged 4.0-litre V8 (producing 603bhp on its own) is paired with a 201bhp electric motor on the rear axle to give four-wheel drive and 804bhp – more than the Ferrari 812 Superfast and McLaren 750S – and a colossal 1047lb ft, which is one of the highest torque outputs yet offered by a combustion-powered road car.

Those figures are enough to send the GT from 0-62mph in just 2.8sec, faster than any AMG road car yet, including the 1049bhp One hypercar. In fact, it's one of the fastest-accelerating combustion cars in production - just narrowly outpaced by the likes of the Porsche 911 Turbo S, Ferrari SF90 Stradale and Lamborghini Revuelto. 

It will push on to a top speed of 198mph, just edging its slightly heavier soft-top sibling.

Power for the EV motor is stored in a 6.1kWh battery that gives an electric range of around eight miles from a full charge, and is topped up on the move via four-stage regenerative braking to ensure "maximum propulsion is always available when the driver needs it", says AMG.

Alternatively, the battery can be topped up at 3.7kW from a domestic charger. 

The car starts up silently on the electric motor if it's set to Comfort mode, but a "powerful, sonorous, AMG-typical" start-up sound is pumped in to the cabin via the stereo speakers. 

The E Performance is almost visually identical to the standard GT – which is offered already with a V8 in two states of tune and a 416bhp four-cylinder – but subtle bespoke cues include the red badging, aero-optimised wheels and the charge port in the rear bumper.

Carbon-ceramic brake discs (larger than the pure-combustion car's) come fitted as standard, as does rear-wheel steering and AMG's active ride control system.

Orders for the new super-PHEV open in autumn. Mercedes has not yet detailed UK pricing plans, but a starting price of around £200,000 looks likely, representing a premium of around £25,000 over the top-rung pure-V8 car.