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2025 Mercedes-Benz G-Class Prototype First Drive: More Comfortable and Competent

New engine, same incredible capability

2025 Mercedes-Benz G-Class Prototype front
  • Revised G 550 sees a turbocharged inline-six with mild hybrid technology replace the previous turbocharged V8.
  • Enhanced comfort, solid performance and reportedly improved fuel economy.
  • New driving modes and an updated user interface are added to off-road ability that must be experienced to be believed.
2025 Mercedes-Benz G-Class Prototype front

The Mercedes-Benz G-Class might be an iconic model, but even it’s not immune to the march of regulation, and Mercedes-Benz has had to adopt a more planet-friendly powertrain for its mighty off-road model. That means the 2025 G 550 replaces the familiar twin-turbocharged 4.0-liter V8 engine with a 3.0-liter inline-six with a 48-volt mild hybrid system. The new powertrain might lose a V and a pair of cylinders over the outgoing eight-cylinder but brings a number of advantages over it, too. 

The benefits start with the power output. The old G 550 delivered 416 horsepower and 450 lb-ft of torque, but this inline-six brings more. Mercedes is not disclosing output for any version yet, but concedes to "around" 330 kW for the European-spec models — or around 442 hp from the gas engine — on this drive, with the integrated starter generator (or ISG) adding around 20 hp. Torque output sees more significant gains, with around 413 lb-ft from the engine assisted by a further 147 lb-ft from the ISG.

All told, the new powerplant offers around 100 lb-ft more torque than the V8 and benefits not just performance. We expect the current model's 0-60 mph time of 5.6 seconds to drop, while on- and off-road the G-Class should haul more, and more easily. The extra power underhood is great, but the changes are primarily executed in a bid to gain efficiency, which was never the V8’s strong point. Expect a sizable jump in fuel economy over the V8’s listed 13 mpg city and 16 mpg highway ratings, then, with Mercedes engineers saying its figures compared favorably to the outgoing G400d turbodiesel model that’s not sold in the U.S. As such, we think a 20-plus mpg highway figure isn’t beyond the realm of possibility here. 

2025 Mercedes-Benz G-Class Prototype rear

More economical, while also addressing our criticisms

A good deal of the economy gains are down to the forthcoming EQ electric G-Class, with the need for Mercedes-Benz’s engineers to squeeze every efficiency gain possible out of it filtering down to the new combustion model. Look closely and you’ll spot slightly differing profile windshield pillars and a "spoiler" on the channel that sits above the windshield — these make a sizable impact on the G’s block-like aerodynamics — without detracting from its chunky appeal. This change, combined with additional sound insulation, results in a quieter interior with notably reduced wind noise.

Mercedes has also addressed one of our biggest criticisms of the current G-Class — its infotainment system. The new model now features Mercedes-Benz MBUX and corresponding touchscreen controls. This and a number of driver assistance and convenience features that are new to the G-Class bring the hot-rod SUV in line with the rest of the Mercedes-Benz range. A new multifunction steering wheel helps control all of that, including the addition of a hill descent mode, a necessity due to the reduced engine braking from the far more efficient powerplant. 

2025 Mercedes-Benz G-Class Prototype profile

More modes, greater capability

Within the new MBUX interface, it's possible to select additional driving modes; a Trail mode joins the existing Sport, Comfort, Eco, Sand and Rocks, and G Mode choices. The Trail mode is for light trails and tracks, though with its separate ladder chassis, three locking differentials, solid rear axle and low-range off-road ratio, the G-Class is capable of scrambling, clambering, climbing and wading with the very best competition, making all surfaces look ridiculously easy to conquer. 

Helping here are improvements to the traction and stability systems, thanks to faster-acting algorithms in the vehicle software — another spin-off from developments for the forthcoming electric G-Class — as well as the more abundant, quicker-accessed torque from the new powertrain.

2025 Mercedes-Benz G-Class Prototype front

Behind the wheel 

The new G-Class feels like something of a throwback, with its upright windscreen, flat flanks and height that are deliberately reminiscent of G-Classes long ago, but it’s not without some impressive modern sophistication. Its agility on the road is remarkable for something this big and heavy, due in part to the G 550’s lighter engine taking some mass out of the nose, which assists the turn-in and feel behind the wheel. 

There’s been a great deal of suspension tuning, too, with revised dampers acting more quickly. The G 550 still rolls slightly in the bends, but does so with a more consistent, progressive movement, which benefits road comfort. On pavement, the G 550 is smooth and comfortable, but where it really reveals itself is on the bumps of mixed snow, ice and road surfaces that punctuate our lengthy drive in Sweden. The G-Class rides with impressive comfort and control on the challenging surfaces — the four-wheel-drive system, in combination with the Falken winter tires, finds incredible grip and traction when on the snow, without feeling compromised on the road. The engine and nine-speed automatic are quick to respond to driver inputs, with the former making a commendably rousing note, though engine-note die-hards might want to go for the V8-powered AMG G 63 model when it’s introduced. 

It all feels like a more mature, more resolved and more capable G-Class, that last element impressive because there are few vehicles with the G’s bandwidth. Only now — with Mercedes' sizable revisions — the compromises once necessary to achieve that have been lessened significantly.

2025 Mercedes-Benz G-Class Prototype rear

And the competition?

The G-Class occupies a niche within a niche, being a truly off-road-capable machine, yet with luxury credentials to have it parked alongside its Gulfstream G550 namesake. It’s a Range Rover rival as much as it is a Land Rover Defender alternative, with other possible contenders for your attention in this upscale marketplace including SUVs like the Bentley Bentayga, Lamborghini Urus and many more besides — including MB’s own GLS. The G-Class has always offered something a bit unique, though, and so it remains, but it does so now with a user interface that’s significantly enhanced and greater parsimony thanks to the revisions made to its new powertrain specification and other detailed enhancements.

Edmunds says

We’ll report back as soon as we’ve driven the G 550 in production specification, but our first drive of the prototype has been revealing. Mercedes has improved on key, overdue areas of concern for the iconic off-roader. It’s quicker yet more economical, has a significantly improved user operating system, feels more agile and composed on the road, and benefits from some refinement — most notably in relation to wind noise at highway speeds. Yes, some will bemoan the loss of the V8 and all that comes with it, but if the price of progress is a vehicle as appealing as the G 550, then it's arguably a price worth paying — in every sense.