The Six-Cylinder G-Class Isn’t for Enthusiasts

Every G-Class sold in America since Mercedes started importing the truck has had a V-8 engine. The G500, the G550, the G55 AMG, and the twin-turbo AMG G63. Every single one has come with eight cylinders (save for a handful of limited-production V-12 models). Now, for the first time, you’ll soon be able to buy an internal combustion G-Wagen without a V-8.

Mercedes dropped the 4.0-liter twin-turbo V-8 from the base G550 for 2025, replacing it with a turbocharged 3.0-liter inline-six paired to a mild-hybrid system. It makes the truck quicker and more efficient than before, and for normal consumers, it’s the better choice. But I still miss the V-8.

That mild-hybrid tech comes in the form of a 48-volt-powered integrated starter-generator (ISG) mounted between the engine and the nine-speed automatic gearbox. Mercedes rates the engine at 443 horsepower and 413 pound-feet of torque—27 more horses but 37 fewer lb-ft than the V-8. The ISG can supply an additional 20 hp and 148 lb-ft of torque at lower engine speeds, though, making the new powertrain feel far peppier while setting off. 

The hybrid assistance makes the inline-six feel like a more responsive and modern powertrain. By strict German numbers-matter-most standards, it’s the better one to have. But it’s just not as interesting as the old 4.0-liter. Gone is the G-Wagen’s signature V-8 rumble, something that made every G identifiable from idle alone. I suspected Mercedes would want to hide the sound of the six-cylinder, but it’s still audible, from inside and outside of the truck.

I don’t mind the sound of an inline-six, but this one isn’t very nice to listen to. At times it can be buzzy and annoying; something I wouldn’t expect of any Mercedes product, much less a G-Wagen. Again, this is something that I suspect most G-Wagen buyers might not care about. But to me, the V-8 was a more enjoyable experience.

The rest of the six-cylinder G-Class is absolutely excellent, though. Mercedes had American journalists drive G500s, the European equivalent of the US-market G550. Sound aside, power delivery for the six-cylinder is smooth and consistent, while the nine-speed delivers solid, unintrusive shifts. Independent suspension and rack-and-pinion steering, introduced on the G-Wagen in 2019, means a car-like front end and laid-back, pleasant cornering characteristics. The suspension is softer than it was in last year’s G, but don’t be surprised if you feel a few more bumps if you’re coming from something like a GLE.

While lots under the hood has changed, not much is different on the outside. Aside from a slightly different grille, new bumpers, and a handful of other tiny changes, the 2025 truck looks identical to its eight-cylinder predecessor. The G-Wagen’s unmistakable silhouette and retro design are as appealing as ever, and we hope it never changes.

It’s the same story inside the cabin. Minor changes are tough to spot, even if you’ve spent time in last year’s model. Some of the switchgear has been redesigned, but all of the buttons, including the three big switches for the differentials and the physical climate control cluster, are still around. Two 12.3-inch screens sit atop the dash; the one behind the steering wheel acts as a gauge cluster, while the other handles infotainment. Sadly the company-wide touch-capacitive steering wheel buttons have made it to the G550, making adjusting the cruise control and volume a bit more annoying than it was before. 

As nice as the six-cylinder G performs on the road, it’s all meaningless if it can’t live up to the nameplate’s unparalleled off-roading capabilities. Mercedes took us to the very off-road park in southern France where it validates the G-Class, giving us the chance to climb up the same jagged rock faces as the engineers. 

Even with rain-soaked slick and muddy surfaces, the G-Wagen made quick work of every obstacle. It’s up some of these rocks that you realize just how invaluable a front locker can be. Engineers demonstrated how the G struggled to climb up an uneven cliffside without the third differential engaged. Press the button on the dash to activate it, and the truck drove right up as if there were no obstacle at all. The G500 and G550 might not be able to perform the same torque vectoring miracles as the electric G-Wagen, but it’s still among the best in the game right now if you need a go-anywhere SUV right out of the box.

No matter how you feel about the switch from V-8 to straight-six power, it might not matter to most G-Wagen buyers. Mercedes representatives at the launch event wouldn’t tell us the split in US sales between the base G550 and the big boy AMG G63, saying only that the G63 had a market share greater than 50 percent. Rumors suggest the split could be as great as 70/30 in favor of the G63. 

The straight-six-powered G-Wagen is the most rational choice, but the G-Class is a passion product. People buy them because of how it makes them feel, not just because it’ll get them from A to B. And if you’re passionate about the G, you’re probably going to want the V-8. So I wouldn’t be surprised if that split grows beyond 70/30 once the six-cylinder G550 goes on sale.