Parkers overall rating: 4.1 out of 5 4.1
  • AMG G 63 is very powerful
  • 0-62mph in just 4.5 seconds
  • Even the diesel G 350 d isn’t slow

Mercedes-Benz G-Class engines infographic

The Mercedes-Benz G-Class's performance is extraordinary for a car designed to scale 45-degree inclines.

Mercedes-Benz G-Class diesel engine

From summer 2019, the somewhat more pragmatic choice of a diesel powerplant is once again available in a G-Class. Quite whether reducing running costs is of primary concern for a G-Class customer where status and/or go-anywhere ability are usually the influencing factors remains to be seen. Still, you’ll be filling it up slightly less frequently given its official claim of 29mpg on the combined cycle.

Ignore the numerical part of the G 350 d’s model designation – it’s not got a 3.5-litre engine. Instead, it’s fitted with one of Mercedes’ new generation of inline six-cylinder motors with a capacity of 2.9 litres.

With 286hp available – that’s 41hp more than the equivalent engine in its predecessor – the G 350 d isn’t slow, although its heft and Nelson Mandela house-like aerodynamics see its top speed clipped to 123mph.

Mercedes-Benz G 350 d rear badge

There’s 600Nm of torque on tap between 1,200 and 3,200rpm, making it easy to modulate slow-speed driving when off-roading, or for making good pace on the black-top – 0-62mph is 7.4 seconds. Extraordinary.

It’s a smooth-running and quiet engine to boot. That rich seam of torque makes overtaking manoeuvres swift and secure, while junction pull-aways never make you feel nervous as it gains alacrity.

It really comes into its own on long, motorway jaunts, sitting effortlessly at the limit, while maintaining efficiency boosting low revs.

Mercedes-Benz G 350 d off-roading

Around town it provides effortless progress – the throttle pedal is easy to modulate, plus it works superbly in conjunction with the adaptive cruise control package, essentially making urban driving a steering-only operation.

Mercedes-AMG G-Class petrol engine

With the AMG G 63 scintillating acceleration is guaranteed. It musters an impressive 585hp and 850Nm from its twin-turbo V8. Combined with excellent traction from the standard four-wheel drive, it’s enough to deliver 0-62mph in just 4.5 seconds and top speed is pegged at 137mph. If you’re feeling brave (and live near a German autobahn), you can specify the optional AMG Driver’s Package to raise the top speed to 149mph.

Expect serious speed from your Mercedes G-Class

All G-Classes are automatic, with no manual transmission option. The 9G-Tronic auto ’box has nine ratios and changes gear seamlessly; most cog-swaps slur away in the background and you are rarely aware of the process of shifting ratios.

The Mercedes G-Class is unusual in having a low-range transfer box; only available at low speeds, it’s like a super-low gear calibrated for off-road use – and is great for extreme engine braking when descending a slope or extra grunt when climbing up steep hills. We’ll discuss more off-road ability in the Handling section below.

  • Built to scale mountains
  • Exceptionally good off-road
  • Significantly improved on-road, too

Mercedes-Benz G-Class: how does it drive?

Old G-Classes were a bit of a mess dynamically: they might have been ace at off-roading and streetside posing, but they were not enjoyable cars to drive. In fact, at times they were downright terrifying.

Mercedes-Benz G-Class: on-road handling

The new one changes all that. At last, the Mercedes G-Class feels at home in all typical circumstances. It will no longer wander all over the lanes on a motorway; the steering is accurate and you can place it precisely on a country lane; and the ride is well-judged, softening out the road scars and acne typical of British roads.

The Mercedes G-Class is far better on-road than the previous version

We can’t recall a bigger quantum leap from what went before. With the last car, you were forever making excuses and reminded of this car’s military origins. With the new G-Class, that is no longer necessary. It rides, handles and steers much like any other modern Mercedes SUV – and we say that as a compliment.

The upright shape makes it very easy to place on the road; one of the best features on the G is the pair of indicator repeaters that rise out of the bonnet like bubble-wrap, clearly defining the outer edges of the set-square design. A parking camera and sensors are standard, making slotting into a space a cinch.

Mercedes-Benz G-Class: off-road performance

Of course, anyone considering a G-Class is likely to be attracted by its off-roading ability. Here, it scores extremely highly. It is unique in having three locking differentials and a low-range transfer case. The former are useful to prevent wheels spinning when on low-grip surfaces (or dangling in the air, if you’re properly off-road and tiptoeing over boulders) while the latter keeps you going even if you’re scaling a 1:1, or 45-degree, incline.

Mercedes G-Class in the sand

Let’s get technical briefly. Mercedes quotes 241mm of ground clearance for driving over rocky terrain, you can wade through 700mm of water, and the G has impressive angles of ramp breakover (26 degrees), approach (31 degrees), departure (30 degrees) and side tilt (35 degrees).

Those figures will be largely meaningless to many readers, but if you do venture off-road at all they will confirm that the G-Class is well equipped when you veer off tarmac.

Mercedes-Benz G-Class off-roading

Parkers tested it on a tough mountainside courses, both in summer, and in winter on packed snow and ice, finding it mind-bendingly capable. You can toggle the differential locks on and off while you’re driving at speeds of up to 30mph but we’d recommend getting instruction if you really fancy making the most of the Merc’s go-anywhere ability. We found the car’s talents outshone our own.

Happily, all that traction and grunt means that the Mercedes G-Class has impressive towing limits: a trailer, caravan or boat of up to 3.5 tonnes can be towed in safety (if the trailer is braked), or 750kg on a more typical, unbraked trailer. All-seasons tyres are standard fit.

Mercedes-Benz G-Class: how much can it tow?

A fixed tow bar is standard on every UK-registered model – and the ESP stability system even includes a programme designed to stop trailers from snaking, which is a welcome comfort blanket to those likely to carry heavy loads regularly.

Mercedes Dynamic Select

Dynamic Select is a drive mode selector, letting you pick between Comfort, Sport, Eco and Individual. Flicking through the modes means you can set up the car's throttle, engine, transmission and suspension settings to deliver a sportier drive or relax everything to a more laidback gait. It works well and changes the character of the car noticeably; you can also set your own preferences in the Individual toggle, which is a neat touch.

Mercedes G-Class in Sand mode