Mercedes-Benz GL63 AMG | PH Used Buying Guide

Big, brutish, and certainly not bashful – but a bit of bargain nonetheless

By Tony Middlehurst / Sunday, 13 November 2022 / Loading comments

Key considerations

  • Available from £26,000
  • 5.5-litre V8 twin-turbo, all-wheel drive
  • Big in every way, including power
  • Lots of tech to keep you (and it) safe
  • Some say it’s one of the silliest cars ever
  • Funny how not many are available to buy


A seven-seat SUV to carry your family around made sense. An AMG with a large-capacity twin-turbo V8 made sense. A seven-seat SUV with a large-capacity twin-turbo V8 made very little sense at all, but that was what was so great about the GL63 AMG that was announced at the LA show in 2013. 

Mercedes called it ‘the S-Class of SUVs’. Before he moved from Autocar to PH, Nic C called it ‘as anti-social as a rocket-powered bus’. With a 5.5-litre AMG V8 grumbling away under its two-storey bonnet the GL63 aimed to put the S into SUV. It didn’t have the full-honk naturally aspirated 6.2 litres of righteous legend, but the twin-turbo M157 did more than hold its end up with 550hp and 561lb ft – enough with 4MATIC all-wheel drive splitting the torque 40/60 front/rear to bulldoze the 2.5 tonne-plus GL through the 0-62mph run in 4.9sec. Top speed was limited to 155mph, which sounded quite enough given the size of the thing.

For some, of course, enough was never enough. In that case, Brabus was happy to sell you a B63S-700 kitted version with 690hp and torque electronically ‘limited’ to a mere 708lb ft at 2,000rpm, supposedly to stop you frying the tyres on the 23-inch  wheels. The 0-62 was 4.6 seconds and the top speed governor was removed to unlock a dreamy 186mph. Seeing a GL bowling along at that rate must have been quite a sight.

By 2015 you’d think Mercedes might have reconsidered the wisdom of a school bus that did around 14mpg in town, but brilliantly things got even more bonkers with the announcement that year (for sales in 2016) of the £102,000 GLS 63. Its extra 27hp and wider spread of torque chopped the 0-62 time to 4.6 seconds. With the AMG Driver’s pack box ticked the top speed was delimited to 168mph. Marvellous! Shipping containers had never moved so fast.

GL63s were nearly £92,000 new, which was £30,000 more than the regular GL350. That premium wasn’t just for the hand-finished AMG engine, although in all honesty, we’d happily pay a hefty wodge of cash for that on its own. Maybe not as much as the M-B parts bod would want for a new one – over £50k, not including installation – but let’s not split hairs. Anyway, the AMG badge meant more than just a magnificent engine. It also meant 22mm wider wheelarches straddling 21-inch wheels, 390mm bin-lid front brakes, quad pipes, sporty seats and steering wheel, top spec generally and Mercedes’ clever roll-inhibiting Active Curve Control to stop you tipping over on bends. More practically, its 5.1-metre length and absence of space-robbing batteries meant you got the full seven-seat capability.

The X166 GLS 63 was replaced in 2019 by the X167 GLS 63 4MATIC+ featuring the most powerful GL engine ever, the M177 4.0 litre V8 biturbo. With 603hp and 627lb ft it was good for a 4.2 second 0-62 time – but wants a measly 4.0 V8 when you can have a not much slower 5.5 V8 for much less money?

How much less? Ah well, there is a small problem there. You’ll have no trouble finding G63s (Mercedes’s hopped-up Defender-alike, as favoured by rappers, boxers etc) but X166 AMG GLs and GLSs are quite thin on the ground. Well, they’re fat on the ground, but you know what we mean. There were no GL63s for sale on PH Classifieds at the time of writing. There were a dozen or so GLSs on there which, by virtue of them being newer, started from around £46,000. We’ll link you to those at the end of this guide.

If you’re feeling frustrated by this expensive-sounding information, the good news is that early higher-mile (90k-plus) GLs are available on the UK used market – just not on PH at the moment – at prices starting from £26,000. That is, quite literally, a lot of car for the money. Is it a lot of trouble for the money though? Let’s get ready to rumble.


Engine: 5,461cc V8 32v twin-turbocharged
Transmission: 7-speed automatic, all-wheel drive
Power (hp): [email protected],750rpm ([email protected],500rpm)
Torque (lb ft): [email protected],000-5,000rpm (1,750-5,250rpm)
0-62mph (secs): 4.9 (4.6)
Top speed (mph): 155
Weight (kg): 2,580 (2,345)
MPG: 22.9
CO2 (g/km): 288 (276)
Wheels (in): 10 x 21
Tyres: 295/40 (295/35)
On sale: 2013 – 2019
Price new: £91,715
Price now: from £26,000

(Figures are for 2013-15 GL 63 (brackets for 2015-19 GLS 63)

Note for reference: car weight and power data are 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.


The M157 engine featured on other 2011-on AMG cars like the CLS63 and E63. It is a mighty unit with variable camshaft adjustment and, on the GL63 at least, an ECO start/stop function to make you think that you’re not continually destroying the planet.

In general, M157 reliability was good but it wasn’t problem-free. Perhaps the most commonly reported issue was stretched timing chains on pre-2013 engines caused by oil starvation on start-up. Mercedes soon put out a modified chain and a check valve to rectify this. As the GL63 came out in 2013 you’d like to think there wouldn’t be an issue with it.

Oil leaks from M157 valve covers were a thing too. This was usually sorted by taking the cover off and putting it back on again. Some owners complained of seizing fuel pumps, injector trouble, and scoring of the two cylinders closest to the turbochargers. Carbon build-up is a normal collateral damage risk associated with direct injection engines like the M157, but it hasn’t been overly complained about by GL owners. GL63 radiators and coolant hoses didn’t last forever and you needed to keep on top of spark plug condition as well. The plugs had a big job to do on this motor and as such could require fairly frequent replacement (15-25k), especially on tuned cars. Tuned GL63s – now there’s a thought.

The model’s uprated fuel-saving Speedshift Plus 7G-Tronic torque converter transmission was set up for comfort rather than speed, which is a polite way of telling you not to expect a blazing response to kickdown commands. Probably no bad thing given the power and torque that was technically available. The box had three modes and an automatic ‘double-declutch’ function for smoother downshifts. Even so, some of these transmissions suffered from surging on shifts between 2nd and 3rd, and/or between 3rd and 4th, with harsh downshifts to first when coming to a halt. This could be improved by a software reset but in some cases the only permanent fix was a new gearbox, which in the US at least would often be done under warranty, with a new transfer case sometimes thrown in for good measure.


GL63s came with AMG Ride Control/Airmatic adaptive air suspension offering up to 11.2 inches of ground clearance, or more with an optional off-road package that also included a bash plate. There were three suspension modes, Comfort, Sport, and Sport Plus, with automatic body lowering to reduce drag and increase stability at speed. You wouldn’t call the ride quality plush in any setting though. There’s a limit as to how much comfort manufacturers can provide when spring rates have to be firm enough just to support a vehicle’s weight.

On the plus side, 63s had Active Curve Control. This did a creditable job of keeping the GL more level through corners than physics suggested it should be. The electro-mechanical steering was speed-sensitive too and actually worked better than you might expect on such a beast. While we’re on the steering, post-October 2015 GL63s were recalled in August 2017 to fix a faulty connector in the power steering system that could cause a loss of assistance. Compressors, relays, hoses and valves failed on a variety of Airmatic-equipped Mercs, this one included, and some cars suffered from leaking ACC pumps, a £2k repair.

Overall the GL63 handled quite tidily, all things considered – and there was a lot of GL63 to consider. Its ability not to fall off the road was a tribute to the engineers at both AMG and Mercedes-Benz who must have lost a few nights’ sleep wondering how to make sure that a grossly huge family vehicle that was capable of entering a corner at a ridiculous speed would also be capable of coming out of that corner in one piece. One of their solutions was to allow the traction control to step in early with cautionary braking if the driver was showing insufficient inclination to do so.

It’s a sizeable lump of motor on these so the engine mounts were prone to taking a beating. There are owners out there who have had to replace them not once but twice, which seems a lot for something that at the time of writing would still be under ten years old. On servicing, expect an independent to charge you around £250 for an A service and a little under £400 for a B service. An official AMG four-service package will be around £2,100.


Size, so they say, isn’t everything, but it was certainly the GL’s main defining characteristic. If you thought an Audi Q7 was big, well, you’d be right, but the GL was even bigger. Sidesteps weren’t just decorative on these. Clearly it was intended for spacious driving environments such as those found in the US and Middle East, rather than the elbow-clamping byways of Blighty. The 5.1-metre length and near-2.0-metre width demanded some degree of care when inching into a typical British car park space.

The braked towing weight was a handy 3,250kg, and you could even lash your lardy mate to the roof as long as he didn’t weigh more than 100kg (and your GL didn’t have the glass roof). Bi-xenon lights were standard along with intelligent lights, which are the ones that can answer pub quiz questions.


As you’d expect from the GL’s range proximity to the S-Class, its cabin material quality was very good, even if the style wasn’t to everyone’s taste. For the 2016-on GLS 63 the Comand screen that had been inset in the GL dash was replaced an 8in ‘separate’ unit. Apple CarPlay and Android Auto were added at this time.

The GL was a seven-seater but the two bods in the third row would always be the poor relations. Still, both of the back two rows were electronically operable, though only in downward mode in the case of the middle row, where your passengers had loads of space and their own climate controls and vents. Luggage space with all the seats up was a reasonable 295 litres, rising to 680 with the third row down and a yawning 2,300 litres with both back rows stowed. The tailgate was electric. Also standard were leather AMG heated sports seats (the door cards, dash and armrests were in ‘Artico’ faux leather), keyless ignition, three-zone climate control, Bluetooth and USB interface, and assistants for attention, parking, speed limits and crosswinds, which are the worst winds.

Some problems were reported on the panoramic roof, an option which we think came with the facility to open the third-row windows from the driver’s seat, a useful feature on hot days if you didn’t want to have the roof open. There were recalls in 2013 for inaccessible child restraint anchor points in the rear seats and in 2016 for under-spec right rear seatbelts in cars built over a three-month period in summer 2015.

Interior options included B&O surround sound, ventilated seats, rear entertainment (screens in the backs of the front seat headrests), a 360 camera, more assistants for lane keep, blind spot and Distronic Plus, M-B’s adaptive cruise control. A Designo pack lifted the leather quality. 


Lewis Hamilton ran a GL for a bit as his company vehicle. Okay, his was the sensible GL350 Bluetec diesel version rather than the GL63, which is slightly disappointing. You could see why he went down that route though. After all, petrol is expensive, hmm. Realistically, though, it does help to have an alternative view on motoring and on life in general to choose a GL/GLS 63 over something equally rortmungous like a Porsche Cayenne Turbo or an SVR Range Rover, but hey, life would be boring if we were all the same.

You buy a 63 for the thrill of owning a £90k vehicle at a third of the price, or because you’re a bit different and want to pull all the back seats out and run Britain’s poshest van, or just because you love the engine. Whatever you decide, probs best if you don’t drive it anywhere near a Stop The Oil demo. It would be wise to look up some warranty cover too. Faults aren’t all that common but when they do crop up repair costs will not be low.

OK, so you’ve decided that a four-second people carrier like the GL63 is the very thing for you and your nervously quaking family. Cliff-like depreciation is your friend. Unfortunately, you’ve got a problem: finding a car to buy. Notionally, the going rate for GL63s is £26-£28k for early (2013) 100k milers, rising to £35k for later (2014) 40-50k mile cars, but as we mentioned at the beginning, GL63s were conspicuous by their absence from PH Classifieds at the time of going to press and the number you’ll find on alternative UK selling sites rarely rises above a handful.

Of course, if you’re a glass-half-full type you could see this as a good sign of happy owners being unwilling to sell. Whatever the reason, your cheapest 63 option on PH as of November 2022 was this 77,000-mile 2016 GLS in Obsidian Black with black Nappa leather, pano roof, electric towbar and four new tyres – no small expense with 22in wheels – at £46,495. Three grand or so more will snip more than 20,00 miles off in this 2017 car also in black. £65k gives you a choice of three sub-30k mile one-owner cars from ’17 and ’18. Of that trio we quite like this one, a very clean looking 2018 car in white with 21,000 miles.

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