With the advent of the Mercedes-AMG GT Concept which broke cover at Geneva earlier this year, here come the first images of a test mule which is said to boast of a hybrid powertrain like that featured in the Geneva show car. EQ Power+ is the sub-brand given to the new crop of electricity-boosted AMGs, which is also the name given to the latest Mercedes-AMG Formula 1 race car.

It joins the Porsche Panamera Turbo S E-Hybrid in the realm of the electrified, high-performance four-door coupe, and if the numbers from the GT Concept are to go by, it will surpass the Porsche’s already considerable output numbers; augmented by a lithium-ion battery pack, the upcoming four-door GT is expected to produce a total system output of around 805 hp, or not far from the Concept’s 815 hp.

The electrified, turbocharged 4.0 litre V8 four-door GT is expected to have pure EV functionality, though its electric-only range has yet to be disclosed. The lithium-ion battery pack will be charged whenever the car is being driven, and will regenerate power from braking or from the internal combustion engine.

Thus equipped, the four-door AMG GT is expected to hit a 0-100 km/h of under three seconds; top speed has yet to be disclosed. Given the state of camouflage cladding, it is perhaps unlikely that it will debut at the Frankfurt Motor Show next month, which could mean a debut at the end of this year or early 2018.