Mercedes-Benz GLS-Class Review (2020-present)
Mercedes-Benz GLS-Class cars for sale
4.0
Expert review
Pros
The presence of an SUV with the luxury of a limo
Roomy and beautifully made seven-seat cabin
Fabulous MBUX infotainment system
Cons
Fuel economy and emissions to make an oligarch think twice
A bit too similar to the smaller GLE
Uncomfortably large for UK roads
The CarGurus verdict
If you can get over the sheer volume of car that the Mercedes GLS presents – and the issues that presents in terms of fuel consumption and manoeuvring on British roads – then you’ll find a very impressive and luxurious machine. Reliability is a concern, as it is with all Mercedes-Benzes, but the GLS gives its occupants huge amounts of space and no small amount of pampering, regardless of which model you go for. That breadth of choice in the range elevates it above the competition in many ways, and that’s helped by a driving experience that’s more capable than a car this large and heavy has any right to be. As an SUV version of an S-Class, it doesn’t feel quite as special or sumptuous as the Mercedes flagship. But as a seven-seater luxury SUV, it’s very good indeed.
Space is cavernous, in the first two rows of seats at least. Most versions come with seven seats across three rows, although the high-end Mercedes-Maybach models come with two individual seats in the back with a storage console between them. In either set up, there’s bags of leg- and headroom, even for taller adults. The middle seat folds down to reveal a centre console, cupholders and, depending on spec, space for a tablet that connects to the infotainment system.
The third row raises and lowers electrically, which saves some effort, but isn’t the fastest system of layout change. Space in the two rearmost seats is at more of a premium, but you can still get two adults in there, which isn’t the case with many rivals.
Boot space will depend on whether you use the third row of seats or not. If you do, it’s still usable for a few bags at 355 litres, which isn’t always the case in other seven-seaters – an advantage of the GLS’s sheer bulk. Use it as a five-seater and you’ll have a massive 890 litres to play with. In the four-seat Mercedes-Maybach model, the boot is set at 465 litres. Not massive, but not tiny, either.
On the move, the GLS feels really, really big relative to its environment, especially on tight urban roads or narrow country lanes. Manoeuvring can be somewhat nerve-wracking as a result, although visibility is very good thanks to the high driving position. But the car’s handling is genuinely impressive for something this big. It’s not set up to be sportscar-like, a la Porsche Cayenne, but it stays admirably flat when cornering. Some may be disappointed with the ride quality though; it’s far from uncomfortable, but comparisons to the S-Class limousine prompt very high expectations, and there’s a firmness to it that doesn’t match such a lofty and wafty benchmark.
We’ve tried the power plant that most people will go for, which is the GLS 400d diesel engine. This uses a 3.0-litre straight six, with 325bhp and lots of torque. That makes for swift acceleration – 0-62mph takes 6.3 seconds – and plenty of effortless mid-range shove, so it never feels slow. For the vast majority of customers, this is all you need.
If you do want extra grunt, then the AMG-tuned GLS 63 may well be more up your street. This uses a 4.0-litre V8 with a monstrous 604bhp, which gives it a 0-62mph time of just 4.2 seconds. There’s also the Mercedes-Maybach model, which focuses more on luxury than outright performance, but it uses the same V8 engine, tuned to 549bhp.
The GLS comes with a choice of diesel or petrol engines, ranging in power from pretty grunty to very muscular, by the time you get to the models touched by Mercedes’ tuning arm, AMG. It’s a direct rival to the similarly-huge but actually-smaller BMW X7, as well as other luxury seven-seaters like the Audi Q7 and Volvo XC90. You might even be considering a Range Rover, Bentley Bentayga or Rolls-Royce Cullinan. What sets Mercedes aside in this battle of the behemoths is the breadth of choice you get in the GLS, from the (relatively) entry-level diesels to the performance AMG models, or the ultra-luxurious Mercedes-Maybach cars.
It looks on paper (and in real life) like a car better suited to wide American roads than the relatively tight British highways, and it’s no surprise that it’s actually built at Mercedes’ factory in Alabama. But the look and interior stay true to the European-built Mercedes, with a sumptuous cabin that’s very reminiscent of smaller cars in the range, albeit with big grab handles on either side of the centre console. This could well be a nod to the fact that the GLS can go off-road, but we’d be very surprised if any owners venture far from the tarmac.
Build and material quality are excellent, as is the infotainment system. Called MBUX, it’s one of the best systems on the market. It looks great, using two side-by-side screens within a single tablet-like bezel. One is a touchscreen in the centre of the car, while the other sits behind the steering wheel in place of traditional analogue dials. The system is controlled either by the touchscreen, or through a touchpad between the front seats, which makes it a doddle to adjust settings on the move. You can also use buttons on the steering wheel or a surprisingly effective voice control system. Apple CarPlay and Android Auto are included as standard for smartphone integration.
If there’s a criticism, it’s that it’s all a bit too samey compared to other, less expensive Mercs, such as the GLE. If you’re splashing out on what Mercedes itself calls ‘the S-Class of SUVs’, you may be expecting something a bit more special.
This is a big, heavy, expensive and luxurious car. If you’re considering it, you’re probably not that fussed about the running costs. But for what it’s worth, you can expect 32.1mpg from the 400d diesel, 22.1mpg from the AMG GLS 63 and 21.1mpg from the Maybach GLS 600 model. Use any of that power with enthusiasm, though, and those figures will drop further. The GLS comes with a 90-litre fuel tank to give at least a reasonable range between refills.
You’ll need to service your GLS every year or 10,000 miles, switching between minor and major. Mercedes offers a service plan for up to four services, with prices starting at £78 a month or £936 up front for two.
Insurance will be pricey, too, as the GLS sits between groups 47 and 50 of 50.
If you’re paying big money for a big, luxurious car, you might reasonably expect bulletproof reliability. Well, bad news; Mercedes does not have a particularly good reputation, and regularly comes in towards the bottom of the manufacturer rankings in independent dependability studies. In fairness, though, so do plenty of its luxurious rival brands. Merc was 26th of 31 in the 2020 What Car? Reliability Survey, and 28th of 30 in the Driver Power customer satisfaction survey, with respondents particularly irked by poor reliability.
The caveat in all this is that the GLS is too new to have any meaningful, model-specific data, so perhaps Mercedes has turned a corner, and it’ll prove more reliable than some of its stablemates. The signs are not positive, however.
- Trim levels in a new GLS start with AMG Night Edition, which features 22-inch alloy wheels, air suspension, LED headlights and a panoramic sunroof, as well as all sorts of other high-end features. It’s far from spartan. But upgrade to AMG Night Edition Executive and you’ll get 23-inch wheels, heated seats all round and a removable MBUX tablet in the back. The AMG GLS 63 is similar in spec, but has black wheels and red-painted brake calipers.
- The luxurious Mercedes-Maybach model comes in standard GLS 600 form, or in First Class trim. The former has exclusive 23-inch wheels, upgraded suspension and a panoramic sunroof, together with soft-close doors and a high-end Burmester stereo, while the First Class has the individual rear seats and folding rear tables. All Maybach models have various two-tone paint options, although be warned: prices start at more than £18,000. Just for the paint.
- Pre-2021 standard GLS models had a slightly different trim range, called AMG Line Premium, AMG Line Premium Plus and AMG Premium Plus Executive. By and large, the features were comparable to the three standard trims mentioned above.
- If you want the best fuel economy: No GLS model is going to be particularly frugal on fuel, but the 400d model will be the least thirsty. Officially, it promises up to 32.1mpg, which isn’t bad for something this big and powerful.
- If you want all the toys: Every GLS is pretty packed with equipment, but if you go for the Mercedes-Maybach GLS 600, you’ll get pretty much everything you can think of, including a sliding panoramic sunroof and 360-degree camera, sound optimised tyres with foam absorbers in them, an interior fragrance system and electric rear blinds. Not enough? How about champagne flute holders, high-pile floor mats and a fridge? That should do it.
- If you want massive power: The AMG-powered GLS 63 is still huge, but more than 600 horsepower will propel it forward faster than some sports cars. And it’ll make a very loud noise while doing it, too.
- If you want to go off-road: All GLS models have 4Matic four-wheel drive, so can tackle a reasonable amount of muck under the wheels, but if you want to do something more serious, go for a car with the optional off-road package. This adds a downhill speed regulation system, low-range gearing and an off-road panel in the centre console, as well as selectable off-road modes that change the car’s settings according to what kind of terrain it’s on.
