The Mercedes-AMG GT 4-door can now flex muscles it didn’t know it had

G-Power’s reputation is one of the foremost BMW tuners in the land. That reputation has laid the foundation for the German tuner to branch out to other automakers, including Bimmer’s crosstown rival, Mercedes-Benz. Take this program for the Mercedes-AMG GT 63 4-door, for example. In keeping with tradition, G-Power is presenting a three-stage engine upgrade program that pulls some sickening power and performance figures out of the AMG GT 4’s 4.0-liter twin-turbocharged V-8 engine. On top of that, G-Power’s new kit for the power-packed four-door luxury Merc-AMG also includes a new set of wheels and a smattering of other cosmetic upgrades that help elevate the AMG GT 4-door’s stature higher than where it’s already at. If you thought the Mercedes-AMG GT 4-door is the most subdued of all AMG GT models, then prepare to be blown away with what G-Power is offering for the high-powered sedan.

What’s G-Power’s exterior upgrade offering for the Mercedes-AMG GT 4-door?

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power Exterior
- image 913060

G-Power’s tried-and-tested tuning formula typically revolves around a slew of upgrades spread throughout a specific car. Cosmetic and aerodynamic upgrades are present, and while these upgrades vary depending on the model, it is a G-Power staple to maximize the overall potential of a car; it’s building a program for. That said, it does come as a bit of a surprise to see that the tuner’s exterior upgrades for the AMG GT 4-door revolve largely around a new set of wheels.

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power Interior
- image 913033

Not that we should take that against G-Power. After all, the tuner is offering a set of drop-dead gorgeous Hurricane RR forged wheels to anyone who wishes to avail them. The high-quality wheels measure 20 inches in the front and 21 inches at the back, ensuring that your AMG GT 4-door is riding on some of the best rims you can buy in the aftermarket world. Even better, a second rim model with a filigree multi-spoke design — it’s called the Hurricane RS — is still baking in G-Power’s in-house wheel oven. Once that set is out, you’ll have another wheel option to choose from.

The rest of the exterior remains largely untouched, though it is worth pointing out, too, that interior upgrades are available based on a personalized basis. G-Power has enough interior dress-up options to make your head spin, but those options are largely available on an inquiry basis.

What’s G-Power’s engine upgrade program for the Mercedes-AMG GT 4-door?

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power
- image 913054

G-Power’s main objective in dabbling with the Mercedes-AMG GT 4-door is to give the high-performance saloon an engine upgrade that’s fit for its stature. See, the AMG GT 4-door is already powered by a 4.0-liter twin-turbocharged V-8 engine that produces a naughty 577 horsepower and 590 pound-feet of torque. It’s capable of accelerating from 0 to 60 mph in just 3.4 seconds, and it can hit a top speed of 193 mph. Those are delightful numbers, but they do not represent the peak of the saloon’s potential. Not by a long shot.

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power Exterior
- image 913039

That’s where G-Power comes into the picture. The German tuner prepared an in-house tuned software program called GP-700. The plug-and-play kit zeroes in on the engine’s ECU unit, unlocking more power in the process. The result is a more powerful twin-turbo V-8 engine that now produces an impressive 700 horsepower and 700 pound-feet of torque. Do the math, and you’re looking at a power boost if 123 horsepower and 110 pound-feet of torque. It’s important to point out that this kind of power already sits well into supercar territory. A 700-horsepower Mercedes-AMG GT 4-door can run with the bulls of the exotic car segment without breaking a sweat.

But the best part of it all? G-Power’s engine upgrade offering for the AMG GT 4-door isn’t done yet.

Wait, there are more engine upgrade programs?

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power Drivetrain
- image 913084

Did you think G-Power’s engine upgrade program was limited to just one software tune? The German tuner is renowned for launching multi-stage engine upgrade programs, and the new kit for the AMG GT 4-door is no different. There are three total stages in G-Power’s program for the high-performance saloon.

The second-stage program involves a similar software procedure, albeit the slightly more potent GP-750 performance kit to go with in-house developed G-Power downpipes. That potent mix helps the twin-turbo V-8 engine produce a whopping 750 horsepower and 737 pound-feet of torque.

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power Exterior
- image 913060

If these two programs aren’t enough to tickle your funny bones, then, perhaps, G-Power’s top-stage performance program will get you up on your feet. A pair of new turbochargers are included in the kit, and those are joined by new downpipes, sports air filters, a stainless steel exhaust system, and, last but certainly not least, G-Power’s GP-800 performance software. All of these upgrades help turn the AMG GT 4-door into an 800-horsepower monster with the same 737 pound-feet of torque output being sent to the wheels.

G-Power didn’t mention the kind of performance gains that the Mercedes-AMG GT 4-door stand to receive with these upgrades. We do know that, in stock form, the performance saloon’s 3.4-second, 0-to-60-mph time, and 193-mph top speed are well established. Given the corresponding power gains, here’s what we think the AMG GT 4 is capable of with these three G-Power engine upgrade kits. These figures are all estimates.

G-Power Kit 0 to 60 MPH Time Top Speed
GP-700 program (Stage 1) 3.0 seconds 200 mph
GP-750 program (Stage 2) 2.8 seconds 205 mph
GP-800 program (Stage 3) 2.7 seconds 205 mph

How much is all this madness going to cost me?

It’s hard to say the total amount of the whole program because the final price will largely depend on the kind of interior upgrades you get. Fortunately, G-Power has announced pricing details for a lot of the items that make up the whole kit. The available set of 20- and 21-inch Hurricane RR wheels, for example, sells for €7,950 and €8,950, respectively. That converts to around $8,930 and $10,000, respectively.

As far as the software programs go, expect to pay a prince’s ransom to avail of any of them. The GP-700, for example, is priced at €2,495 ($2,800). The mid-level GP-750 program, on the other hand, will set you back €2,995 ($3,300). Then there’s the GP-800, which G-Power is selling for €3,595 ($4,040).

The two turbochargers that are included in the Stage 3 kit sells for €6,390 ($7,200) while the downpipes are priced at €5,360 ($6,000). The sports air filters only cost €238 ($270), but the stainless steel exhaust will set you back €4,850 ($5,450) on its own.

Suppose that you want the top-of-the-line package from G-Power, you’re looking at a price north of $40,000 without anything happening to the interior of your AMG GT 4-door. Add some fancy leather and Alcantara in the cabin, and your total cost could approach $50,000 for the program alone to go with the $140,000 price tag of a brand new 2020 Mercedes-AMG GT 4-door.

Final Thoughts

2020 Mercedes-AMG GP 63 Bi-TURBO by G-Power Exterior
- image 913066

This is G-Power we’re talking about, so, of course, we have great things to say about the G-Power GP 63 Bi-Turbo. In true G-Power form, the German tuner was able to maximize the potential of the Mercedes-AMG GT 4-door without compromising the identity of the performance saloon. All the items included in the program are all carefully curated to fit together seamlessly. There’s nothing excessive about any of the items; everything just fits into what the AMG GT 4-door is all about. With the G-Power kit, the AMG GT 4-door now has more power on tap, but it’s a refined kind of power that should appeal to performance fiends and classy owners alike. Add another feather to your cap, G-Power. You did it again.

  • Leave it
    • Pricey program
    • The Mercedes-AMG GT 4 can do without it
    • Hard to access if you’re not from Germany
Kirby Garlitos
Automotive Aftermarket Expert - kirby@topspeed.com
Kirby’s first exposure into the world of automobiles happened when he caught Knight Rider on television as a five-year old boy. David Hasselhoff didn’t leave much of an impression on him (that happened later on in Baywatch), but KITT certainly did. To this day, Kirby remains convinced that he will one day own a car with the same ‘spirit’ as the original KITT (not the 2008 monstrosity). He doesn't know when that will be, but until then, he’s committed to expressing his love for KITT, and all cars for that matter, here at TopSpeed.  Read More
About the author

For over 35 years, the brand G-POWER has been synonymous with first-class performance tuning that catapults any basic vehicle into unknown realms of power and performance. For many years, the focus was on the M top models from BMW, but G-POWER has long since widened its gaze to become a specialist in AMG optimizations as well. This made obvious sense, firstly because AMG operates in the same sector as M GmbH, and secondly because G-POWER’s corporate headquarters in Bavaria is not only very close to Munich, but also a stone’s throw away from Affalterbach. On top of that, many proud owners of BMWs given the G-POWER treatment also had AMG models parked next to them in their garages, and thus wanted to have these overhauled by their favorite tuners too.

The G-POWER power upgrade is available for numerous AMG 63 models, which house ferocious four-liter M177 Biturbo V8 engines beneath their front hoods. Take the AMG GT 63 4-door coupé, for example, which G-POWER has now turned into the GP 63 Bi-TURBO. Customers have the choice between three boost levels: The strongest variant gives the AMG GT 63 a mighty 800 hp of power and a maximum torque of 1,000 Nm, which is made possible thanks to the combination of GP-800 performance software (€3,595*) with new turbochargers (€6,390*) and downpipes (€5,360*) as well as sports air filters (€238*) and a stainless steel exhaust system (€4,850*) by G-POWER. This improves performance, torque delivery and responsiveness and, at the same time, optimizes engine efficiency and fuel consumption. In spite of all this, all factory engine protection and diagnosis functions are left untouched. This maximum power level catapults the GT into the league of thoroughbred super sports cars.

The middle level gives the AMG 750 hp and also a maximum of 1,000 Nm, which in this case is down to the installation of GP-750 performance software (€2,995*) and the G-POWER downpipes. Finally, the starter package provides 700 hp and up to 950 Nm, which is achieved simply by G-POWER’s GP-700 performance software (€2,495*). The advantage of all G-POWER upgrades is, firstly, the big-brand level of quality provided by the production process that satisfies the famously stringent German standards. Secondly, they have been extensively tested at high speeds on the autobahn, in other words they have been specifically and explicitly developed and conceived for operation in the absolute full load range. The praise of G-POWER customers speaks volumes: “The car should have been made like this in the first place...” is the prevailing opinion.

As a cosmetic upgrade, the G-POWER GP 63 Bi-TURBO sports the company’s own HURRICANE RR forged wheels – which are available in either 20" or 21" (€7,950* or €8,950*, respectively). Furthermore, a second rim model with a filigree multi-spoke design – the HURRICANE RS – is currently under development, which will soon add to the top-quality G-POWER range.

View the full press release Hide press release
Press release

Related Articles

2019 Mercedes-AMG GT 4-Door Coupe

What do you think?
Show Comments
Car Finder: