Bavarian tuner G-Power has revealed its latest performance upgrade for the Mercedes-AMG GT R coupé, saying it has unearthed the "untapped potential" of the twin-turbo 4,0-litre V8.

So, what sort of potential has been realised? Well, the engine now generates a whopping 588 kW and 850 N.m, which is sent to the rear axle via a tweaked seven-speed transmission.

The increased power and torque come courtesy of the firm’s V4 performance software and a Hurricane RS engine conversion. The modifications include upgraded turbochargers, a racing fuel pump and lightweight forged pistons. Sports air filters and downpipes with sports catalysts have been fitted, too.

G-Power has yet to announce the tuned GT R’s performance figures but, for reference, when we tested the standard model in January 2018, the engine's 430 kW and 700 N.m managed to propel the coupé from standstill to 100 km/h in 3,77 seconds. Affalterbach claims a top speed of 318 km/h.

The G-Power GT R rides on 20-inch Hurricane RR alloys up front, with 21-inch items fitted at the rear. The “high-tech” aluminium wheels are shod in Michelin rubber, measuring 275/30 fore and 305/25 aft.