The Posaidon RS Is A Mercedes-AMG GT63 S 4 Door With Nearly 900bhp

The Mercedes-AMG GT 4 Door Coupe has a rather problematic name. It’s not really an AMG GT, it’s technically a five-door car, and just because it has a sloping roofline doesn’t automatically make it a ‘coupe’.

And yet, the GT ‘4 door’ is a tremendous piece of kit. It drives much sharper than a car of that size really should do, and it’s monstrously fast. With the GT63 S developing 630bhp and cracking 0-62mph in just 3.2 seconds, it has more than enough power. At least, that’s what we think - German tuner Posaidon is inclined to disagree.

Its riposte is called the RS 830. The tuning pack blesses the GT’s M177 4.0-litre twin-turbo V8 with new turbochargers, upgrades for the charge air-cooling system, performance air filters, freer-flowing downpipes and less restrictive catalytic converters. Working together with some software fiddling, you’re looking at 819bhp and 811lb ft of torque.

The 0-62mph time drops to 2.9 seconds, and with no limiter spoiling the party, the RS 830 will keep going until 217mph. The package - which includes gearbox control software tweaks - is €24,000

Want more power? You really shouldn’t, but for anyone not satisfied by that hilarious output, there’s also an ‘RS 830+’ options which bumps the GT up to 868bhp and 885lb ft.

If you’d prefer a different Merc with a silly power output, all of these upgrades are available not just on other M177 V8-powered AMGs, but also the M178 engines used in ‘proper’ AMG GTs.