Mercedes-AMG G63 | PH Used Buying Guide

• Available for £105,000
• 4.0-litre V8 petrol twin-turbo, all-wheel drive
• Goes and stops incredibly hard 
• Beautifully put together inside and out
• Dynamically much improved over the old 5.5
• Main buyer negatives are fuel consumption and high used prices  

Although many couldn’t quite believe it, the second-generation Mercedes-AMG G63 was launched in January 2018 at the Detroit show. Why was it so hard to believe? Well, by that point Mercedes’s Geländewagen had been around in essentially unchanged form for nearly forty years, after being introduced in 1979 as a military vehicle and then turning into an alternative to the Land Rover that had been chugging around war zones and other road-free parts of the world for the previous thirty years. 

For 2019 Land Rover finally moved its Defender on from body-on-frame to a lighter and much more modern unibody design. Mercedes must have thought about doing something similar to the G-Class, or about getting rid of the G-Class altogether to save a whole heap of R&D money. Surprisingly they did neither. Instead, they stuck with the separate chassis design historically so beloved by serious off-roaders, if not so much by those seeking ultimate comfort on the highway. 

A workaday W464 version of the G-Class is still available in some markets. Powered by a 181hp/443lb ft 3.0 diesel, the G350d won’t quite crack 100mph. Indeed, you can get them in restricted 75mph or even 50mph flavours. That’s niche. 

The W463 AMG 63 version that is the subject of this buying guide is at the opposite end of the G-Class scale. It’s an expression of corporate chest-beating that must have given Land Rover’s board pause for thought after they’d signed off on the new Defender. Should they have stuck with separate frames? They’ll never know.

In this guide, we’re going to focus on the 2018-on G63 powered by the M176 4.0-litre twin-turbo V8. Built by hand at the Magna Steyr plant in Graz, Austria, the gen-two G63 was wider, taller and longer than its predecessor. Most of its extra length was between the front crumple zone and the rigid chassis to get the car through upcoming pedestrian safety regs. It was unclear how well a sub-100kg pedestrian would fare against a solid flat surface travelling at 30mph with nearly 2,600kg of Mercedes behind it. Presumably it’s the thought that counts. In the main though the new car was entirely recognisable as a G-Class, Mercedes having resisted the temptation to give the windscreen more than one degree of extra slope and having refused to bin classic G-Class bodywork tics like bonnet-mounted indicators and visible door hinges. 

It says something about previous G-Classes powered by V12s, a 5.4-litre supercharged V8s and a 5.5-litre turbocharged V8 that the 4.0 V8 seemed almost ordinary by comparison, but of course the M176 was already well proven as an exciting and spectacularly effective unit that any other manufacturer would have been proud to have in its range. 

Two ‘hot vee’ twin-scroll turbos ensured there would be no shortage of power (577hp) or torque (627lb ft) in the new G63. That was a little less than the M176 went on to put out in the 2019 GT 63 S four-door coupe but it was more than that produced by the AMG GT R. In the G63 it added up to a mid-four second 0-62mph time and a top speed of 137mph, or an autobahn-friendly 149mph when the delimiting Driver’s Package box was ticked (£2,000). Side-exit exhausts delivered lots of inappropriate, or highly appropriate, gurgling. 

Reflecting the G’s transition from rufty-tufty off-roader to luxury on-roader, the new G63’s 4MATIC all-wheel-drive system gave you a 40/60 front/rear torque split compared to the 50/50 of the preceding model. However, to keep the ‘gripped’ fraternity on side, the transfer case’s Low Range off-road reduction gear was changed to 2.93 to 1 over the old one’s 2.1 to 1 to aid takeoff on extreme uphill gradients or help you get over inconvenient boulders. ‘G Mode’ was the official phrase for the driving mode when this off-road gear or one of the G63’s three 100 per cent diff locks was activated. Mercedes claimed that no other production vehicle had that many diff locks and who are we to argue?

The G-Class has been wooing a certain demographic since AMG jumped onto it in 1999 and to this day they still attract customers, some of whose work you might not entirely approve of. The normal, or you might think hackneyed, G63 ‘look’ is tints, dark exteriors and eye-popping interiors, topped off with a perched stance on 22-inch (or bigger) wheels wearing rubber-band tyres. Some, like this earlier 5.5 are blinged up to beyond the max. 

None of it matters because, irrespective of bejazzle, the demand for G63s is strong enough to fend off most of what the rest of us have to put up in the depreciation department. The cheapest 4.0 G63 on sale in the UK at the time of writing in April 2024 was a privately owned example from 2018 with 83,000 miles, 48,000 above the average for the model and year. The price of that one was sternly set at ‘£105,000, no offers’. At the same time, similarly early dealer cars with slightly above average mileage (50k) were starting off at just short of £110,000, representing a drop of only £33,000 off the new price of £143,000 in 2018. 

All these numbers suggest a good reputation for reliability. Is that borne out by owner experiences, though? Were there enough advances to make the revitalised G63 a genuine rival to the mighty Range Rover?  Let’s dive in and have a look.  

Engine: 3,982cc V8 32v twin-turbocharged petrol
Transmission: 9-speed torque converter auto, all-wheel drive
Power (hp): 577@6,000rpm
Torque (lb ft): 627@2,500-3,500rpm
0-62mph (secs): 4.5
Top speed (mph): 137 (149 with Driver’s Package)
Weight (kg): 2,595
MPG (WLTP): 17.4
CO2 (g/km): 369
Wheels (in): 20
Tyres: 275/50
On sale: 2018 – on
Price new: £143,305
Price now: from £105,000

Note for reference: car weight and power data is hard to pin down with absolute certainty. For consistency, we use the same source for all our guides. We hope the data we use is right more often than it’s wrong. Our advice is to treat it as relative rather than definitive. 

AMG said that the G63’s combination of a 4.0 V8 with two twin-scroll turbos and M-B’s Speedshift TCT 9G transmission delivered a sense of effortless superiority.  The burble from the twin side-exit exhausts also delivered a sense of naughty hilarity, which may be one reason why so many of these cars have blacked-out windows. After all, nobody wants to be annoying other road users with the sight of a madly grinning mush. That’s a real risk with the G63. It was playful even before you pressed the enloudening button that ramped up the exhaust cackle to a daft level. It is an attention-grabbing car in many ways, so don’t buy one if you wish to maintain a low profile or would like to be let out at junctions.

The G63’s Speedshift TCT 9G transmission had an old-school selector stalk on the right side of the steering column but there was nothing old-fashioned about its responsiveness or the performance it unleashed. Tromp on the throttle and you were instantly off, irrespective of how comfortable a driving mode you were in. Bespoke software shortened shift times and allowed multiple downshifts in the 2018 car, with an ‘emotional’ double-declutch function in Sport and Sport Plus modes. Even with nine gears and all that torque it always stepped off the line in first. It all underlined Benz’s determination to keep the G63 true to AMG’s sporting roots despite its unlikely appearance. Although the official 0-62 time was 4.5 seconds, independent testers have seen times beginning with a three.

These are not cheap cars to run. Those who have bothered to work these things out say you’ll get 2.6 miles for every pound you spend in normal use. The official fuel consumption was between 17 and 18mpg, achievable partly through the deactivation of four cylinders on partial loads, but leaning on the loud pedal on such an aerodynamically inefficient vehicle would drop that to something nearer to 10mpg. Long-term test G63s run by magazines and websites have averaged out at between 16mpg and 18mpg. 

Annual road tax in the UK is £600. You won’t see dealer servicing prices online but we’ve seen independents apparently quoting £260 for the A service and £380 for the B, which seems almost suspiciously reasonable. 

In this version, AMG magically managed to work real improvements into the car’s road manners without losing the G-Wagen’s off-road abilities. The new G63’s suspension recipe included double wishbones mounted directly to the ladder chassis at the front, a new rigid beam axle rear with Panhard rod, steel coil springs, anti-roll bars and AMG Ride Control with adjustable adaptive damping. A new brace running between the tops of the front suspension towers helped to boost torsional rigidity by more than 50 per cent.

The resulting improvement in stiffness put the handling generally and the ride quality in particular leagues ahead of the bouncy old 5.5 G63. Steering feel was on another level too, thanks to the horribly vague recirculating ball system being replaced by a more contemporary rack and pinion arrangement. It was still a meaty steer but the difference in precision was chalk and cheese. This was the first big-boy G-Class you could take to the track and genuinely extend without needing to have a recovery truck driver on speed dial. 

Wisely, AMG didn’t build any oversteer into the G63 equation as that would have been a step too far on something with a pickup-like roof height of almost two metres (check your local multi-storey car park). Still, within its safety margins the G63 was remarkably driveable. Understeer arrived eventually, as you’d expect with such a tall vehicle, but its onset was predictable and safe. Standard tyres were Goodyear Eagle F1s or Pirelli Scorpions. In a crash stop the brakes were powerful enough to close the sliding manual cover sunroof. 

Off the circuit and onto an ordinary road, ideally one that wasn’t too narrow, the G63 was great – comfy, cushy and secure. Off that road and onto the mud, it was every bit as competent as more dirt-dedicated tackle like the Wrangler Rubicon. Engaging a G63 diff lock by pressing one of the three chunky switches in the centre of the dash gave you a choice of off-road modes, including Sand, Trail or Rock. Increased between-the-axles ground clearance provided a new wading depth of 700mm, still well below the new LR Defender (800mm in 130 guise) but good enough for most non-apocalyptic scenarios. 

There have been reports of leaky seals on early low-mile cars, both the rear main and others connected with the steering apparatus. This resulted in either unsightly stains on your driveway or (in the case of the rear main) in noxious clouds of white smoke caused by liquid dropping onto hot exhausts. Owners who put 24-inch wheels and 33-inch tyres on their G63 often noticed that there was some rubbing and extra harshness to the ride. Ah well. 

At 2.4 tonnes you couldn’t really call the G63 a light car, but the recent legitimisation of high vehicle weights by electric vehicles has at least made it less of a standout in the portliness stakes.

The car’s boxy shape and slim pillars meant that blind spots weren’t an issue. The bodywork was a mixture of high-strength steels and aluminium but the doors shut with an iron finality that would be more familiar to whoever shuts those big vault doors in Swiss banks on a Friday evening (do they still do that?). You needed to put real effort into shutting G63 doors but that was all part of the fun. The noise of remote door locking and unlocking was likewise wonderfully OTT.

As you might hope for at these rarefied price levels, metallic paint was a no-cost option and if you fancied a change from the usual silver, white or black there were some standout colours to choose from like Hyacinth Red or Ultra Violet. £2,700 bought the Night Package which added extra menace to the exterior look.

Some owners noticed vibration in their outside mirrors at higher (well, 55mph plus) speeds. Dealers reckoned that fixing it was a simple matter of replacing the mirror motor but that didn’t always seem to resolve it. One dealer actually admitted to the owner that they couldn’t fix it. Another owner found that it could be sorted by putting some tape on the round caps at the bottom of the housings that gave access to the motors and that (on his car anyway) were loose. 

The design of the LED headlights was a nice nod to the style of the original G-Wagen. There could be whistles at speed that was at first thought to be down to the air con side vent because the whistles stopped when you turned the AC off. In fact, it was almost always a faulty window seal that would generate noise when the airflow through the car was changed by turning the AC on. These seals were fixed under warranty. 

One famous journo said that the G63 had less measurable cabin space than a C-Class estate. If that’s true, then Mercedes has done a very clever job of giving G63 passengers the impression that there is actually loads of space in there. Maybe the illusion works because the space provided was so very well configured for the humans who would be inhabiting it. 

Front seat passengers still had a dash handle to grab at, as per the G-Class tradition, and they also had leg and shoulder space aplenty, which was not so G-traditional. Tall folk might mumble about a lack of legroom in the back though. The heated massage seats were excellent, with adjustability for side bolster grip. You could option Dynamic seats which physically hugged you. Clever seat base extenders on the standard seats curled out from underneath, leaving no sticky sweet-catching gap between the seat base and the extension. 

A heated steering wheel and parking assist were standard, as was adaptive cruise. The G63’s lane assist function was executed by the braking system, which could feel weird on the road. The steering column-mounted gear selector on the other hand made perfect sense, as did the toweringly high driving position, surely one of the loftiest in production. The running boards were functional and built to be used. 

The driver’s section was freshened up for the new G63, Mercedes’s wide-screen cockpit being built around two 12.3-inch displays blended into one. The left side did the infotainment, the right one the driver data. The Mercedes Me app worked well, as did Apple CarPlay, but a chunk of the screen was blacked out if you were using Android Auto. 

The digital instrumentation was superb as was the surround-view camera. The top-down ‘drone’ view was very handy for wheel protection when you were negotiating width restrictors, branches and/or rocks. There was more than a hint of E-Class or even S-Class about many of the parts used, lending the cabin a much more opulent air than had been the case previously.

The interior generally was very high quality, including the wood that used to be a weakness on German motors. You could choose from 64 rather beautiful ambient light colours. The IWC clock was a nice touch but it was positioned too low to be much use as a timepiece. Wind noise was surprisingly subdued for a car of such uprightness. Double-glazed windows undoubtedly helped there, but random cabin noises could be a thing. 

Miscellaneous squeaks that sounded like they were coming from the driver’s side dash or the driver’s headrest would more often than not be the result of friction between the sunroof and the headlining. You could normally sort that by treating the area with clear lithium grease. 

Some Comand screens needed their securing bolts tightening. Leather instrument binnacles have rubbed against plastic vent covers, once more resulting in squeaking. The solution in this case could be again down to bolt-tightening, but doing that wasn’t so easy because of poor access. Inserting some felt tape between the rubbing parts was an easier and effective fix. Some cars had rattles from one or more of their 15 Burmester speakers. Again AMG dealers seemed to be at a loss as to how to fix them. Not their speciality, presumably. Shame because otherwise this audio system was brilliant.

Most would say that the new 4.0 G63 was a big enough improvement over the old one to put it on the shortest of any short lists on which a full-fat Range Rover also appeared. In 2018 you could get a Bentley Bentayga or a badass Range Rover Sport SVR for the same £140k+ as the G63, and if you threw a bit more money into the pot you could even be in a Lamborghini Urus, but the attitude of the G was a strong draw. 

It’s a shame that the urge to pimp these cars was also so strong because that distracted from its inbuilt talents. In completely standard trim the G63 had more than enough character for anyone. If you felt insecure about its (and maybe your) place in the world, you could always hunt one down with a factory Magno paint scheme in purple or whatever. No need to wrap it in gilt leaf or stick bin liners over the windows – unless you really wanted to spend all day waiting for someone to let you out of a side road. 

Keeping it standard made sense at trade-in time too, if you ever reached that point. You might not because they’re hard to part with. Why is that? Well, there was always the noise and the utterly bombastic presence, but now with the 2018-on version there was also very acceptable handling and more than acceptable comfort. The G63 had finally become a realistic daily vehicle. 

Another big draw with the G-Class has always been its endurance, not just in terms of its ability to handle difficult terrain without breaking but also in terms of its lasting presence in the Mercedes catalogue. As Land Rover found with the Defender, constancy is very appealing to a certain sector of the motoring market and the G perfectly toes that line. 

It’s going to continue to toe it too. As we went to press in the early spring of 2024 manufacture of this G-Class generation was about to stop. However, not only will there be a successor, it will once again be a fully recognisable ladder-framed (sort of) G-Class. There will be a smaller electrified one as well, but the G63 followup will have the same 4.0 V8 powertrain, albeit mildly hybridised, and there will be only minor EQG-inspired concessions to the efficiency-hurting effects of the wind. It will also have the very promising (and early Citroen) sounding electrohydraulic ‘kinetic’ accumulator-and-spheres suspension adapted from AMG’s SL and GT sports cars. According to early drives, this system brings even more significant benefits in roll suppression and ability both on and off the road. 

The important thing is that this car is still getting serious engineering investment from its creators. As far as we’re aware no date has been set or even mentioned for the end of G-Class production. And we like that.

The trouble with good cars is that they’re not cheap. Discounts on new G63 prices, if you can find any, will be minuscule. The most accessible used 4.0 G63s on PH Classifieds at the time of writing all came in at a whisker under £110,000. That would get you a 2018 or 2019 example with around 50,000 miles on it, like these two in black. Taking 10,000 miles off that would add at least £6k and more like £10k to the price. Here’s a blue ‘un at just under £116k. £130k takes you to 2020 cars with 20k on the clock, like this one. 

For those who feel they need more attention what about this Hell Green Carbon edition from 2023? With 10,000 miles on it, the price was a fiver under £170k. For those who feel they’re getting the wrong kind of attention here’s a fully armoured blastproof example at a mere £490k. If that’s slightly too steep you could save £160k by buying this nearly-new 700hp Brabus Widestar.