Is the regular Mercedes-AMG G63 just a little too tame for you? Well, in the unlikely instance that’s the case, you’re in luck – because German tuner Posaidon has developed a range of aftermarket upgrades to increase the already-impressive firepower of the G-Class.
In standard trim, the imperious G63 SUV packs a 4.0-litre, twin-turbocharged V8 that hammers out 577bhp and 627lb ft. That monstrous muscle is dispatched to all four wheels via a nine-speed automatic transmission and, despite weighing in at a whopping 2560kg, the Mercedes-AMG can sprint from 0-62mph in just 4.5 seconds. Flat out, if you’re feeling bold, the flying brick will reach an electronically limited 137mph; with the optional AMG Driver's Package, it'll hit 149mph.
If that's not enough, tick all of Posaidon’s upgrade boxes and the output of the 4.0-litre V8 will climb to a blinding 927bhp and 943lb ft. That unlocks a comical 0-62mph time of just 3.6 seconds, which is on a par with the flagship Mercedes-AMG GT-R coupe, while the top speed rises to an electronically limited 174mph.
The heady power gain of over 60 per cent is achieved with a pair of uprated turbochargers, a new exhaust system, ported cylinder heads and revised and improved valve seats. Posaidon also carries out some electronic tweaks, updating the transmission and engine control unit, and fits a water/methanol injection system; this permits significant hikes in output while reducing the chance of engine-damaging detonation.
Such performance commands a predictably hefty premium. The list price for a standard Mercedes-AMG G63 is £146,490 and the Posaidon G63 RS 830+ upgrade, which gets you to 868bhp and 885lb ft, will cost you £27,100. Beyond that, if you want the full-fat 927bhp experience, you’ll have to spend an additional £4000 on porting, £1700 on the valve seat modifications, just over £8600 for the labour to do both and approximately £5300 on the water/methanol system and other minor parts.
Altogether, it’ll set you back some £47,000 for the additional 350bhp and 316lb ft. Paying £134 for every extra horsepower is a pretty alarming figure but, if you’re looking to spend nigh on £150,000 on a G-Class and tune it, the cost is probably moot. You might want to set aside a fair chunk of money for repairs, mind, given that such significant performance upgrades will merrily obliterate the factory powertrain warranty.
The installation of the parts will require the removal of the engine from your G-Class, which is among the reasons the labour costs are so high, but the turnaround is pretty swift; Posaidon says, if you drop the car off and collect it, that the complete installation and configuration will take just a few weeks.
Posaidon offers more than just mechanical and tuning options, too, so you can spend even more if you’re in a position to do so. Cosmetic upgrades, different paint and bespoke modifications are all part of the company’s remit; the custom RS 830+ pictured, for example, features a vented carbon fibre bonnet that helps reduce engine bay temperatures.
The company appears to have a fine eye for detail, judging by elements such as the neatly machined inlay for the water/methanol tank filling point, which bodes well for the quality of work elsewhere. However, at these power levels on the standard rotating assembly, the engine and drivetrain's lifespan may vary considerably.
With some extra work, that said, you might be able to get even more out of it; Posaidon, as a case in point, has already managed to get the twin-turbocharged M177 V8 to produce over 1000bhp and 1033lb ft in its project Mercedes-AMG E63 RS 850+. Whichever way you cut it, question marks about longevity aside, almost doubling the factory output is an impressive feat.
Keyword: Posaidon dials the Mercedes-AMG G63 up to 11