2026 Mercedes-Benz G450d review: Australian first drive

The diesel G is back, baby.

V8 engines and the iconic G-Class have been closer than bread and butter for so many years, and often the only choice of powertrain for those who want to buy the unmistakable Mercedes-Benz 4x4. There were other trim levels available once upon a time, but the big-dollar AMG G63 has been the only mainstay in the range for years.

When many think of a G-Class, they think of the audacious G63 with its bellowing side pipes, blinged-up exterior and eye-watering price tag.

But you could argue it's the more humble and pragmatic six-cylinder diesel that sits closer to the core and spirit of the G-Class. Diesel was there right at the beginning, with a sluggishly slow but hellishly reliable OM616 2.4-litre engine providing motivation, along with a slightly gutsier five-cylinder engine available.

Diesel power hit a high-water mark with the revered OM606 diesel engine, which was a six-cylinder unit with a 3.0-litre capacity.

That engine layout lives on again here, with the G450d. It replaces the short-lived G400d, brings impressive outputs, and puts this automotive icon into a different – and dare I say more pure – lens.

Calling the 2026 Mercedes-Benz G450d cheap is a cop-out, because it's still priced at more than $200,000.

However, it's much cheaper than the G63 AMG ($368,400) and electric G580 ($249,900). With this model starting at $214,900, we've also got a starting price that is lower than the previous diesel G400d ($246,500).

So, what do you get for the spend?

There's leather on the inside, with electric front seat adjustment and heated front seats. There's also electric steering column adjustment, open-pore walnut wood trimming and interior ambient lighting. However, we don't get front seat ventilation in this trim level.

There are twin 12.3-inch infotainment and driver displays on the inside, three-zone climate control, and the Burmester 3D sound system is comprised of 18 speakers and 760 watts.

On the outside, 18-inch wheels can be wrapped in either highway-terrain or all-terrain tyres (depending on which you prefer), LED headlights, a sunroof, and all of those exterior design elements that define this vehicle.

So no, it's not the blingy 22-inch wheels of the AMG, nor do you get the chromed-up exterior and hectic side pipes. But I reckon this car still carries huge presence regardless.

If $200,000 is too much for a G-Class, but you're still dying to get behind the wheel, then check out what is available on Drive Marketplace. It's been around for a while, and there are a few older examples that have gone through a little bit of depreciation.

There's no doubting that strong presence of the G-Class from the outside, where it grabs attention with ease. But on the inside, you might be surprised to find an interior that feels a little bit small and pokey.

The quality of construction and materials is excellent, with the interior feeling like it's been hewn from stone and wrapped in nice wood and leather. Its touch points all feel really nice as well, through the air vents, buttons, shifter and steering wheel.

The windscreen remains upright and flat – in keeping with the heritage of this model – and there is a noticeable narrowness to the cabin.

In a way, there is a familiarity between this car and the likes of a 70 Series LandCruiser or old Land Rover Defender, through the seating position, boxy visibility and width of the cabin. Of course, this one just has a thick smothering of luxury over the top. But it's also countered by some rubber floor mats, which are durable and practical for real-world usage and longevity of the interior.

But the second row could be a sticking point for those who want to parlay this machine into a bit of family usage. There's not a whole lot of leg room on offer, which can make big adults up front and either baby seats or more adults in the back a little bit compromised.

The quality of materials continues, along with that outrageous sense of build quality. But the unchanged nature of the G since the late '70s does come with a compromise here.

Case in point, with the little locking knobs on the doors of the G-Class that you don't really see these days. Door locking mechanisms are gloriously mechanical still, and emit this hugely satisfying sound in operation, somewhere between a bank vault and a bolt-action rifle.

The squared-off shape of the G-Class means boot space is quite good, though, giving plenty of space to load up your stuff. The side-hinged door and rear-mounted spare do eat into space, though, and can be tight to open in a shopping centre carpark.

Twin 12.3-inch screens in the new G-Class offer your information for infotainment and the driver, which is a number mimicked across many other makes and models these days. So just because you're spending the big bucks here, you're not getting one of those gigantic screens like you get in other Mercedes vehicles.

But let's be honest, screens any bigger wouldn't be in keeping with the vibe.

There's quality instead of quantity, though, with a slick MBUX infotainment system that provides plenty of easy usability and functionality. Augmented-reality navigation is quite cool, and potentially helpful in the native navigation, and we also have Apple CarPlay, Android Auto and digital radio.

There's also remote connectivity through the in-built sim card and Mercedes Me app.

Even though it might have some of the better crash-testing ads on record, the current diesel-powered G-Class is not officially included in the ANCAP wrap of crash testing undertaken back in 2019. It's worth noting that we effectively have a new generation model here, which is known as W465 and arrived in 2025.

The current ANCAP rating goes only for the current G63 and discontinued G400d. Plus, this rating is set to expire at the end of this year.

But at the same time, the G-Class doesn't really change dramatically between generations.

The safety equipment is here in the G-Class, but the crucial thing to say is that it doesn't get in the way of your everyday driving. Some of the features were pre-emptively turned off in our test cars, which stayed off when you cycle the ignition on and off.

So if you prefer a more traditional and straightforward driving experience – which matches the flat-plane windscreen and boxy aesthetic – you're in luck here. Less beeping and bonging, and more onus on the driver to pay attention.

But for those lapses, a smartly tuned lane-keep assistance system helps to keep you on the straight and narrow, and the rear-cross traffic alert will assist while reversing in open areas, along with the quality 360-degree camera system.

Expensive car, expensive insurance. In the least surprising part of this review, you're looking at a sizeable chunk of cash each year to insure your G against misadventure or accident. According to our calculations, you're looking at $6458.79 per year in insurance costs for this vehicle.

This is a comparative quote for a 35-year-old male living in Chatswood, NSW. Insurance estimates may vary based on your location, driving history, and personal circumstances.

Mercedes doesn't miss you for servicing costs on this vehicle as well, with a service plan package costing $7800 for the first five years or 60,000km. And while there isn't any form of pricing guide beyond this point to reference, we would hazard a guess that it wouldn't be getting any cheaper.

Even though we've got some relatively stonking outputs here – and aerodynamics inspired by a garden shed – fuel economy is kept in check by the diesel engine, helped somewhat by the 48-volt hybrid system.

A claim of 9.4 litres per 100 kilometres is impressive for a vehicle of this size, shape and weight. And considering you've got enough punch to get from zero to 100km/h in under six seconds, it's even more impressive.

In our testing, we saw a number that hovered around the 11L/100km mark, after a full day of country driving, performance testing and off-roading.

There's one overriding word that defines the experience of the G-Class: solid.

Adopting independent front suspension in recent years has helped the G feel a little more direct and less agricultural through the steering wheel, but this is still a vehicle that doesn't dance about elegantly like a modern SUV with forward-thinking underpinnings.

It's not uncomfortable nor 'choresome' like you might get in other old-bones four-wheel drives. But it feels heavy and solid over rough surfaces, owing to those heavy-duty underpinnings that have defined this four-wheel drive for decades.

The steering keeps up with a meaty feel, but is also quite direct and responsive from that initial turn-in. Roadholding feels pretty good, but there's also no escaping the size and weight. It's best enjoyed at more of a cruise, dialling in a moderate speed through the sweepers as you enjoy that subtle sense of over-engineering that permeates from within.

The diesel engine is unbelievably refined and well-mannered, emitting zero chatter or clatter that you would normally associate with a distillate-drinking donk. Start-up is smooth thanks to the 48-volt mild-hybrid system, and it stays that way from idle up to the middle and upper ranges.

No, it's not the same thundering thong-slap and ridiculous performance of the V8. But it's still responsive and fast nonetheless, and plenty fast enough for most use cases. It's well managed by the nine-speed automatic transmission as well, which never felt like it was going to put a foot wrong during our test drive.

And because of the full-time four-wheel-drive system here, that 750Nm makes it to the ground with impressive decorum. And let's be honest: 270kW is an outrageous figure for a diesel four-wheel drive.

There's a range of driving modes to cycle through in the G450d, which does give a different experience to the driver. Mostly, it's the dampers, which can stiffen up and slacken off noticeably. Softer is generally better from my point of view, adding a little bit of extra absorption to that solid firmness of the Geländewagen.

This plays into the off-road capability as well, where dedicated off-road driving modes tailor the suspension and driveline to suit challenging tracks.

Once you get off-road, you can feel the inherent happiness and capability of the G-Class shine through. Especially without the 22-inch wheels, which is like sticking high heels on a rugby player, this feels more like the genuine article that – despite the fashion and luxury link-up – this vehicle has always had at the core.

Even though we've gone to independent front suspension with this latest version, the G-Class feels impressively solid (there's that word again) and stable off-road. Our testing was mostly on steep and flat tracks that didn't test things too much, but a short drive on some heavily eroded tracks highlighted great poise.

It's worth pointing out the old live-axle G-Class was always a stiffly sprung vehicle at the front, as the German engineers chased more on-road dynamics instead of off-road flexiness. But this doesn't flop around unstably like other IFS vehicles off-road. Instead, it keeps its feet planted impressively well, putting down traction confidently.

In other words, it's not about the triple lockers, which are always great things to have. Instead, it's more about the inherent capability of the car built into the chassis and suspension, with the diff locking being another layer on top of that.

Whereas most big four-wheel-drives carry the benchmark 3500kg braked towing capacity, it's a surprise to learn that the G-Class cannot match the likes of a Defender or LandCruiser in this regard.

Towing capacity is limited to 3175kg, which is still a good number. But, it's beaten by just about every other four-wheel drive out there. And to make matters worse, the towball downforce limit is capped even further at 255kg.

It's a strange one, because the 6700kg gross combination mass is set up to accommodate more than the GVM and max towing capacity.

A 2535kg kerb weight and 3200kg GVM yields a 665kg payload, which is also potentially a little underdone for some more serious users.

There's something undeniably special about this car. Something that transcends regular rationale and saw me justifying the high price tag and scheming how to afford one.

On one hand, you can get a tough old-school off-roader in the form of a LandCruiser 76 Series, Ineos Grenadier or Jeep Wrangler Rubicon at significantly less money. But, they aren't the same thing as this G, which just feels so freaking solid and anomalous from anything else on the road.

On the other hand, the modernised Land Rover Defender combines similar vibes with luxury touches, epic powertrains and good overall decorum. And you can get a whole lot of Defender for the same money you're spending here.

But, the Defender goes about its business in a different way to the G. It's more of a modern twist on the forebear, rather than being a direct relative.

If I were buying, I'd be taking this diesel G over the AMG model every day of the week. It feels like a truer representation of the model. One that's happier in the mud and sand, rather than poncing around the leafy suburbs.

It's a huge amount of money, but in some ways it's buying you a huge amount of vehicle. Not quantity, but quality. Solidness, density and heritage that make this G-Class special forever.

Sam Purcell has been writing about cars, four-wheel driving and camping since 2013, and obsessed with anything that goes brum-brum longer than he can remember. Sam joined the team at CarAdvice/Drive as the off-road Editor in 2018, after cutting his teeth at Unsealed 4X4 and Pat Callinan’s 4X4 Adventures. Off-road writer of the Year, Winner - Sam Purcell

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