Mercedes-AMG G63 (2025) — a body-on-frame SUV that accelerates like a sports car

The G-Class was conceived as a work vehicle for military and commercial customers, and for its first forty years that’s exactly what it was. The AMG version flipped the whole idea while leaving the construction untouched: the same ladder frame, the same three differential locks, the same upright face — plus a twin-turbo V8 under the bonnet. What actually works on the road, and what stays part of the image, is what we go through here.

In short. The 2025-model G63 is an updated W463A with 48-volt electronics and a reworked suspension. The engine is unchanged, the twin-turbo V8 M177; the stated power figure needs a caveat — see the technical section. 0–100 km/h in 4.3s, top speed 220 km/h.

What this car is

The model has existed since 1979 and has been built in Graz from day one, home to Austria’s Steyr-Daimler-Puch, co-developer of the first generation. The looks have genuinely barely changed: flat panels, external door hinges, an upright windscreen, round headlights. The claim that “the G-Class hasn’t changed in forty years” is, however, wrong in substance — under that unchanged shell, four technical chassis generations have come and gone, along with suspension type, body materials, gearboxes, and the entire electronics suite.

The key turning point came in 2018, with the move to the W463A. The frame was new, the track wider, and up front, independent double-wishbone suspension replaced the solid axle. Part of the audience worried this would undermine off-road ability — a solid axle offers more suspension articulation. The three differential locks and the low-range gearing were kept, though, and on tarmac the car changed radically: body roll and steering precision moved closer to an ordinary luxury SUV.

AMG versions arrived in the late 1990s and went from the supercharged G55, through the naturally aspirated 6.3 and the V12 G65, to today’s four-litre twin-turbo V8. From model year 2025, the range’s petrol engines gained a 48-volt electrical system with an integrated starter-generator that adds torque at low revs. In parallel, a fully electric G580 with four motor-in-wheel units instead of a mechanical transmission has existed since 2024.

This particular car is model year 2025, in Obsidian Black, with a stated 585 hp and 850 Nm. Compared with the 2023 G63 in the same fleet, the main difference is the 48-volt system and the updated suspension.

Technical

The M177 is a four-litre V8 with two turbochargers, from the same family that powers AMG’s sports sedans and coupés. In the G63 it’s paired with a nine-speed AMG SPEEDSHIFT automatic, permanent 4MATIC all-wheel drive, a transfer case with low range, and three differential locks.

The figure of 220 km/h here isn’t an error, and it isn’t a limiter that could be removed. It’s a structural ceiling: a car with an upright face and flat sides has a drag coefficient of around 0.48, and a high centre of gravity plus off-road tyres make higher speeds pointless anyway. The press occasionally mentions versions with a 240 km/h ceiling on a special package, but that doesn’t apply to this car: both the model listing and the reference data give 220.

The model-year-2025 update is the 48-volt starter-generator. It doesn’t turn the car into a hybrid in the usual sense — there’s no electric-only range — the electric motor adds torque at low revs, smooths out the stop-start system, and takes the edge off the hesitation when getting two and a half tonnes moving from a standstill. On the road that’s felt as a firmer response in the first few metres, not as extra performance at speed.

How it drives

Reviews are unanimous in describing the G63 through a contradiction: a very heavy, tall car with a boxy, truck-like silhouette that accelerates and sounds like a sports car. The acceleration is theatrical rather than alarming — the V8 fills the cabin with bass, the body squats at the rear, and 4.3 seconds to 100 on a car shaped like this makes more of an impression than the same number in a low-slung coupé.

The updated active suspension has noticeably improved on-road behaviour compared with earlier generations. Body roll in corners is still there — it can’t be engineered away at this height — but the car no longer demands constant small steering corrections on a straight, and it’s softer over broken surfaces.

There are two honest complaints, and both are worth accepting upfront. The first is fuel consumption: specialist reviews call it one of the worst in the segment, a direct result of the mass, aerodynamics, and all-wheel drive with low range. The second is wind noise at speed: the upright windscreen and external door hinges do their part, and at 130 km/h the wind is noticeably more audible in the cabin than in an ordinary SUV of comparable class.

The off-road capability, though, is real, not decorative. Three locking diffs, low range, and a ladder frame — a combination most crossovers simply don’t have. There’s almost nowhere to use it on a rental, but it’s exactly why the car is built the way it is.

Interior and practicality

The five seats here are genuinely usable, including the middle rear seat — a rarity for a car people buy for its image. Seating position is upright and high, forward visibility is excellent thanks to a flat bonnet with corner markers, but looking back through the narrow window with the spare wheel mounted on the door means relying on the cameras.

Dimensions are the main practical issue. A body-on-frame SUV is larger than most crossovers, and in Prague that’s felt in two places: underground car parks in older buildings, and the narrow streets of Malá Strana and the Old Town. Before booking, it’s worth checking whether the car fits your parking space by height and width.

The boot door swings open sideways rather than lifting up — a holdover from the old construction. It needs clearance behind it, so parking tight against a wall or another car isn’t a good idea if you plan to get things out. Boot volume in the five-seat body with its flat vertical walls is bigger than the exterior dimensions suggest, though.

One more detail you notice once you’re behind the wheel: the step height. An older passenger or a child has a harder time climbing into the G63 than into an ordinary crossover, and the running board can get slippery after rain.

In Czech conditions

The rules in the Czech Republic are the same for every car, but some of them read differently for a heavy, tall SUV.

Speed limits: 50 km/h in town, 90 outside a built-up area, 110 on a road for motor vehicles, and 130 on a motorway. The stated 220 km/h means nothing within that system, but mass and stopping distance mean a great deal — it’s worth keeping more distance from the car ahead than usual.

Alcohol: Czech law has no permitted level. Any alcohol in your system rules out driving, and drinking during the trip is prohibited too. Neighbouring Austria, where the route below leads, has a 0.5-per-mille threshold, but that’s no reason to relax on the way back across the border.

Headlights: on year-round, dipped beam or daytime running lights, in any weather, at any time of day.

Vignette: the Czech electronic one lives in a register and is tied to the licence plate, not a windscreen sticker. Austria needs its own, and it applies from the very first metre of Austrian motorway or expressway — the Czech one doesn’t work across the border, and vice versa. An extra charge for specific tunnels and passes exists in Austria, but it doesn’t come up on the route below.

Winter tyres: the Czech window runs from 1 November to 31 March, and the obligation kicks in whenever there’s snow, ice, or frost on the road, or a reasonable expectation of it. Minimum tread depth is 4 mm. In Austria, passenger cars have no calendar dates at all — the obligation is purely weather-based — and the tread-depth requirement for a radial winter tyre is the same, 4 mm. Chains aren’t mandatory by themselves in either country: only where a specific sign requires them.

There are no low-emission zones in force in any Czech city today, and Austria has no equivalent of the German sticker for passenger cars — what it regulates instead are sectional speed limits and truck bans.

Where to go. Linz makes sense for the G63, and not because of the city itself but because of the kind of road that gets you there. The route: D3 out of Prague through Tábor and České Budějovice to the border at Dolní Dvořiště, then the Austrian B310 and A7 through the Mühlviertel. The Czech portion runs 172 kilometres, but there’s no continuous motorway on the route: a twelve-kilometre gap near Kaplice is routed around on the ordinary road I/3 through towns, and is due to close by mid-2027. On the Austrian side, the planned S10 expressway to the border hasn’t even broken ground, so the first few kilometres past the border also run on an ordinary road. That exact mix of motorway, village streets, and two-lane stretches is the scenario where a heavy, comfortable SUV beats a low-slung sports car. The gap affects the vignette too: on the I/3 bypass stretch, none is required, because it’s a first-class road, not a motorway.

And on the border: there are no systematic checks at internal Schengen borders, but the Austrian side occasionally introduces temporary controls and extends them, so a spot document check is entirely possible — it’s worth checking the current status right before departure.

Who it suits and who it doesn’t

It suits scenarios where the car needs to feel equally at home outside a hotel in the centre and on a dirt road to a country house. It suits a group of five — here that’s not a formality, it’s five genuinely usable seats. And it suits a route like the one described above, where surface quality changes several times over the trip.

It doesn’t suit a tight urban scenario: the dimensions, the side-swinging tailgate, and the step height turn ordinary parking into a task. It doesn’t suit anyone who cares about fuel consumption — it’s high, and no 48-volt system changes that. And it doesn’t suit anyone after a fast motorway car: 220 km/h, the aerodynamics of a brick, and wind noise at speed make the G63 a car for presence, not for outright speed.

The previous G63, from 2023, without the 48-volt system, is the Mercedes-AMG G63 2023. If you want the same power in a low, fast body, there’s the BMW X5 M Competition. Terms for this car are on the Mercedes-AMG G63 2025 page.

Frequently asked questions

Why does a 585-hp car have a top speed of only 220 km/h? Because of its shape and purpose. A body with an upright windscreen and flat sides has a drag coefficient of around 0.48, the centre of gravity is high, and the tyres are built for off-road use among other things. The limit here is structural, not an electronic add-on that can be removed. Acceleration stays quick regardless — 4.3 seconds to 100.

How does this G63 differ from the 2023 G63? By model year and power electronics. From model year 2025, the range’s petrol versions gained a 48-volt electrical system with an integrated starter-generator that adds torque at low revs and smooths out the stop-start system. The suspension was updated too: the active suspension is softer over broken surfaces. The engine remains the same four-litre twin-turbo V8.

Is this a genuine off-roader, or just for looks? Genuine by construction. The ladder frame, permanent all-wheel drive, low range, and three differential locks — front, rear, and centre — all survived the 2018 move to independent front suspension. Most crossovers don’t have that combination at all. It’s a different question whether there’s anywhere to actually use it on a rental.

How many people actually fit? Five, including the rear middle seat — genuinely usable here, not nominal. Seating position is upright and roomy, and the boot, with its flat vertical walls, holds more than the exterior dimensions suggest. Bear in mind the high step: an older passenger or a child will find getting in noticeably harder than in an ordinary crossover.

How hard is it to park a G63 in Prague? Harder than most cars in the fleet: it’s a large body-on-frame SUV, and height and width limits in the historic centre’s underground car parks become a real issue. The tailgate swings open sideways, so you need clear space behind the car. Cameras and sensors help, but it’s worth checking your parking space’s dimensions in advance.

Do I need a separate vignette for Austria? Yes. The Czech electronic vignette only works inside the Czech Republic and is tied to the car’s licence plate; the Austrian one is bought separately, and it’s required from the very first metre of Austrian motorway or expressway. That said, on the Czech first-class-road bypass stretches, including the one around the gap near Kaplice, no vignette is required — the system only covers the motorway network.

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