2025 Mercedes-Benz G550 First Test: The Joy of Downsizing
Can losing two cylinders really improve Mercedes’ living anachronism?
Pros
- The smaller engine is better
- Much improved braking
- Still feels like a G-Wagen
Cons
- Price increase
- No more V-8 rumble
- More efficient but still not very efficient
Forty-five years ago, Mercedes-Benz introduced the Geländewagen, which was immediately shortened to G-Wagen. Some years later, it was properly integrated into Mercedes’ product lineup as the G-Class. Mercedes offered the first models with four-, five-, and six-cylinder powerplants. The first V-8 appeared in the G-Wagen in 1993, 14 years after it launched, when the modernized W463 replaced the original W460.
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Why the history lesson? Well, when Mercedes decided to update the G-Wagen in 2019 (though the company curiously and confusingly decided to hang onto the W463 chassis code), the G550 (then called the G500) had a 4.0-liter twin-turbo V-8 as the model’s “base” engine here in the U.S. Mercedes refreshed the G lineup in late 2024, turning out the updated W465-chassis vehicles, and the G550 now packs a 3.0-liter turbocharged inline-six mild hybrid. Is this downsized powertrain a step up? Or Gelände-flavored sacrilege?
The New G
We got an early taste of what the 2025 Mercedes-Benz G550 would be like last winter in Norway and Sweden. Up in the Arctic Circle we reported the new, smaller-engine G feels “exactly like a G-Wagen.” Mercedes engineers who were present said the new version makes more horsepower but less torque, and without the old V-8 version around to sample, we just had to nod and note the differences. We can say the 2025 Mercedes G550 by no means felt slow and that its handling—on a giant frozen lake, so get out your grains of salt—felt particularly fleet for a G-Wagen. Also, it seemed like the new touchscreen would be a welcome improvement over the previous generation’s scroll wheel. Most important, however, and this goes back to our initial impression, the new G felt every bit as bank-vault/panic-room solid and secure as any other G, eight-cylinder or not.
Put to the Test
That said, here at MotorTrend we’re in the business of testing cars, and we can see better than most other outlets the effects of switching from a stonkin’ twin-turbo V-8 to a 48-volt mild hybrid I-6. Before we get to our test numbers, though, let’s point out the new 2025 Mercedes-Benz G550 made it to the finalist round of this year’s SUV of the Year competition, and if the price wasn’t so damn high ($181,610 as tested) it might have done even better. We said the G550 “drives like greased money” and that it features an “undeniably beautiful interior.” So yes, MotorTrend drivers collectively are big fans of the new G550. But now let’s see what the numbers say.
Weight is the first one that pops out. You might think that by dropping two cylinders the off-road beastie would lose a couple pounds—but that’s not the case. The 2019 G550 we previously tested with a 4.0-liter twin-turbo V-8 weighed 5,665 pounds, which is by no means light. That said, the new version is porkier, gaining 13 pounds for a total of 5,678. For comparison, a diesel Chevy Silverado 1500 ZR2—a much larger but just as capable off-roader—clocks in at 5,770 pounds. So no, the Geländewagen ist nicht licht. Dimensionally, nothing whatsoever has changed between the W463 and W465 G-Wagens. And really, what’s 13 pounds?
We mentioned earlier that the power is up, yet torque is down. Horsepower rises from 416 to 443 as torque drops from 450 to 423 lb-ft. The pounds-per-pony ratio drops from 13.6 to 12.8, which sounds significant. Taking all that into account, along with the 13-pound weight gain, the following numbers make sense. The 2025 Mercedes G550’s 0–60-mph time improves a little, falling from 5.4 seconds for the V-8 version to 5.2 seconds for the new inline-six. Looking closely at the data, the new G550 just gets out of the hole two-tenths quicker, hitting 30 mph in 1.8 seconds compared to 2.0 for the previous model.
But what about in the quarter mile? The extra horses pay off here, as the 2025 G550 beats the 2019 model by 0.1 second, 14.0 to 14.1. However, the V-8 traps faster, moving at 98.4 mph as opposed to just 95.8 mph. That strikes us as odd, as trap speed is typically a function of horsepower. The more you have, the higher your velocity at the end of 1,320 feet.
Could any of this be down to gearing? Nope. Both SUVs use the same Mercedes-designed and built nine-speed automatic and axle ratios. But if you are looking for one big reason to replace your W463 G with a W465, it’s braking. The old G550 stopped from 60 mph in 136 feet, whereas the new one needed only 115 feet. Remember the Chevy ZR2 from above? It’s a 20-foot-long truck. So picture a panic-stop scenario, and you realize why the new G stopping 21 feet shorter than before is a big deal.
In terms of handling, look, it’s a Mercedes G-Wagen. That means performance driving should be pretty far down on your list of considerations, along with rear seat comfort. The new G barely pips the old one in terms of roadholding, 0.62 g vs. 0.61—you’d have to be a datalogger to notice the difference. There’s a bigger difference on our handling course, the MT figure-eight test. Here the 2025 model needed 29.8 seconds to complete the 1,600-foot lap, compared to 30.7 seconds for the V-8 version. Neither time is anywhere near good or even decent. For example, the diesel ZR2 did it in 29 seconds flat. But these are the instrumented differences between the V-8- and I-6-powered G550s.
Things That Matter
There’s one more set of numbers to consider, those that directly impact your wallet and the larger world: miles per gallon. The old G550 was rated at 13/17/14 mpg, terrible by any reckoning. Whereas the new one with two fewer cylinders can eke out 17/19/18 mpg according to the EPA. Still not good but much better than before. Brakes aside, fuel economy is the largest difference between these two generations of G550s.
Ultimately, the new, improved six-cylinder G550 is quicker, brakes better, handles better, and is more than 28 percent more efficient than the eight-cylinder truck that came before. Sure, there’s no V-8 rumble, but we think G550 customers will be just fine with that. Besides, that’s what the G63 AMG version is for, right?
When I was just one-year-old and newly walking, I managed to paint a white racing stripe down the side of my father’s Datsun 280Z. It’s been downhill ever since then. Moral of the story? Painting the garage leads to petrolheads. I’ve always loved writing, and I’ve always had strong opinions about cars.
One day I realized that I should combine two of my biggest passions and see what happened. Turns out that some people liked what I had to say and within a few years Angus MacKenzie came calling. I regularly come to the realization that I have the best job in the entire world. My father is the one most responsible for my car obsession. While driving, he would never fail to regale me with tales of my grandfather’s 1950 Cadillac 60 Special and 1953 Buick Roadmaster. He’d also try to impart driving wisdom, explaining how the younger you learn to drive, the safer driver you’ll be. “I learned to drive when I was 12 and I’ve never been in an accident.” He also, at least once per month warned, “No matter how good you drive, someday, somewhere, a drunk’s going to come out of nowhere and plow into you.”
When I was very young my dad would strap my car seat into the front of his Datsun 280Z and we’d go flying around the hills above Malibu, near where I grew up. The same roads, in fact, that we now use for the majority of our comparison tests. I believe these weekend runs are part of the reason why I’ve never developed motion sickness, a trait that comes in handy when my “job” requires me to sit in the passenger seats for repeated hot laps of the Nurburgring. Outside of cars and writing, my great passions include beer — brewing and judging as well as tasting — and tournament poker. I also like collecting cactus, because they’re tough to kill. My amazing wife Amy is an actress here in Los Angeles and we have a wonderful son, Richard.Read More
