Mercedes-Benz GLS Review 2024

If you need a seven-seat luxury SUV in your life, but an Audi Q7 or Volvo XC90 just don’t have the space, the image or the theatre to cut it, then you need to kick things up a notch. That’s where the Mercedes-Benz GLS comes in. This car is so enormous that it can’t fail to get you noticed, while the desirable badge on the nose and the handsome styling will ensure that you’re being noticed for all the right reasons.

There’s enough space in the passenger compartment and boot to deal with the needs of any family, even one made up entirely of basketball-playing beanpoles, while the amount of luxury kit and clever infotainment tech on board will keep everyone entertained. In principle, a very similar car to the BMW X7, and if you’re considering one of those, you’re probably considering one of these.

You don’t get a choice with the engine of your Mercedes-Benz GLS, because there’s only one. Called the GLS 400 d, it’s a 3.0-litre, six-cylinder engine with 330PS, and importantly, it’s muscular enough to haul this huge car around briskly and easily. It’s also smooth enough and quiet enough to ensure that life in the cabin stays as sophisticated and as civilised as it should in a luxury SUV.

There are three trim levels to choose from, all of which are ludicrously named (we’ll come onto that later), but even the entry-level one has all the luxury gear that you could want from a car like this. Upgrading to the other ones adds lots to the price, and while some of the items (massaging rear seats, anyone?) are quite appealing, many of them are needless fripperies, even in a car like this.

There’s no shortage of options for luxury SUV buyers, but there’s one car that’s more of a direct rival for the Mercedes-Benz GLS than any other. It’s from that old enemy over in Bavaria, and it’s called the BMW X7. The two cars are about the same size (enormous, then), cost about the same (new or used) and provide a very similar mix of quality, luxury, desirability and seven-seat practicality.

Also vying for your cash will be smaller, cheaper seven-seaters like the Audi Q7 and Volvo XC90, while buyers might also consider the daddy of the luxury off-roaders - the Range Rover - if they only need five seats.

As a big, luxurious - not to mention expensive - prestige SUV, you’d expect the Mercedes-Benz GLS to be pretty strong here, and it doesn’t disappoint. All the materials in your eyeline are sumptuously textured and thoughtfully finished, while even most of those that are more hidden away feel of a similarly high grade. Each trim comes with a subtly different combination of leather tones and wooden inlays, but all versions feel as posh as each other.

The build quality is very solid, too, although there are one or two places - like the window switches, for example - where things feel a little more lightweight and hollow than they do in an Audi Q7 or BMW X7, and as a result, the Mercedes GLS doesn’t feel quite as dense or substantial overall.

Aside from the quality on show, the cabin’s wow-factor is provided by the two glass-fronted 12.3-inch screens that are mounted side-by-side in front of the driver. These take many of the car’s various functions, plus the information that would usually be delivered through traditional analogue instruments, and presents them all in one integrated unit. 

The system is controlled either by tapping and swiping the left-hand screen, or via a touchpad and shortcut buttons located on the partition between the front seats. The graphics are super-sharp and the menus have a fairly logical layout, but the touchpad controller isn’t a patch on the iDrive rotary dial you get in the BMW X7 because it's less precise, and more distracting as a result. That said, you can also operate the system via a sophisticated voice control system that’s designed to recognise natural speech rather than specific commands, and it works very well.

All the infotainment functionality you’d expect is supported - DAB radio, sat-nav, Bluetooth, Apple Carplay and Android Auto - as are a few things you might not expect. A wireless phone charging plate and a Burmester surround sound system are included as standard, while the navigation has augmented reality, which overlays instruction graphics over a camera image of the road ahead of you, pointing out precisely where you should be going.

The mid-range trim adds a pair of fixed entertainment screens in the middle row so passengers can get access to various parts of the infotainment system’s functionality, while top-trim cars also get another wireless charging plate in the back and a detachable tablet.

There’s absolutely loads of space up front, and those in the middle row also get a vast amount of head- and leg room, allowing even tall passengers to stretch out. The Mercedes-Benz GLS is more comfortable than most when seating three across the middle bench too, thanks to the sheer width of the cabin and a transmission tunnel that’s flat and low so you can comfortably sit with your feet on top of it (although the BMW X7 is better because it doesn’t have one at all).

The middle-row chairs slide, recline and fold electrically, and they move far enough out of the way to allow pretty good access to the third row. If they’re much over six foot, those in the very back might want to ask those in front to use their electric seat sliders to donate a little bit of leg room, but there’s still a shade more than you get in the Audi Q7 and Volvo XC90, although the BMW X7’s third row is roomier on both leg room and head room.

That said, the boot is still a really impressive size at 355-litres even with all the seats in place, almost as big as a Ford Focus. Fold the third row down (electronically, of course), and you get an absolutely vast luggage space of 890-litres, while dropping all the rear seats gives you van-like carrying capabilities at 1470-litres. 

To accommodate all this space the Mercedes GLS has a big footprint at 5213mm long, 2157mm wide (including mirrors) and 1823mm tall. 

There’s only one engine available in the Mercedes-Benz GLS, and it’s a 3.0-litre, six-cylinder unit with 330PS. Considering the car weighs almost two and a half tonnes, it really has its work cut out, but it actually copes really well. The 0-62mph time of 6.3 seconds even sounds pretty racy, but in reality, the car builds speed in a brisk, effortless way. 

Picking up speed on the move isn’t a problem, either, although if you bury the right-hand pedal to ask for a sudden surge of acceleration, the nine-speed automatic gearbox needs a second or two to decide which gear to give you. In fairness, this is something that also afflicts pretty much all the Mercedes GLS’s rivals, and it’s nowhere near as bad in the big Mercedes as it is in some.

Otherwise, the gearbox behaves impeccably, switching ratios smoothly and cleanly and mostly getting its choice of gear right first time.

Refinement is another of the diesel engine’s strong suits. It stays impressively smooth at all times, and in most circumstances, it’s quiet enough that you might forget it’s there. It’s only when the revs rise - which they hardly ever do, given the engine’s prodigious low-down torque - that it starts to make itself heard.

Wind noise is also really well isolated from the cabin, and that’s even more impressive when you consider that the Mercedes-Benz GLS’ colossal size and upright front-end styling gives it all the aerodynamic slipperiness of a wardrobe. The fat tyres do kick up a bit of a rumble on the motorway, but it’s nothing that’ll bother you. Overall, this is a very quiet way to travel.

The Mercedes-Benz GLS hasn’t been crash-tested by Euro NCAP yet, but every Mercedes tested since 2014 has received the full five stars and there’s little reason to suspect that the GLS would be any different. Besides, you can take solace in the fact that if you crashed into a building in the GLS, you’d probably knock it over.

You can also take solace in an absolutely heaving list of standard safety kit. All cars get a suite of clever safety measures that includes automatic emergency braking, blind spot monitoring, active speed limit assistance and active lane keeping, along with at least seven airbags. AMG Line Premium Plus trim adds active stop and go (the car will automatically follow in line during traffic jams), while AMG Line Premium Plus Executive trim ups brings the airbag count to nine.

Parking a car as enormous as this could be a challenge, so there are sensors and cameras all around the car, along with a parking assistant.

Mercedes-Benz generally performs well for reliability, ranking 13th out of 30 manufacturers in the latest HonestJohn.co.uk Satisfaction Index with an overall satisfaction score of 87.9%. Mercedes SUVs tend to be quite reliable with the smaller GLC scoring an average of 9.5 out of 10 for reliability. 

It should come as no shock that a car as expensive to buy as the Mercedes-Benz GLS will also be expensive to insure. The car sits in either group 48 or 49 according to which trim you choose, and group 50 is the most expensive group there is. Still, if you’re wealthy enough to even consider a Mercedes GLS as your family charabanc, then shipping a few extra quid to the underwriters is unlikely to bother you too much.

If you buy your Mercedes-Benz GLS used rather than new, you’ll avoid the steep first-year ‘showroom tax’ charge that gets rolled up into a car’s on-the-road cost. In the case of the GLS, this is £1850, which is always worth saving. After that, VED tax will be on exactly the same level as rivals. 

Because all Mercedes GLS of this generation were released after April 2017, and all cost over £40,000 when new, all are subject to a surcharge on their annual VED rate for being an ‘expensive car’. That means you’ll pay £325 on top of the flat rate of £150 for the next five years on the car’s life, but from the sixth year onwards, it’ll drop to just the flat rate.

Recently, Mercedes has embarked on a frankly ludicrous policy of calling all its trim levels pretty much the same thing on some cars. And as such, the Mercedes-Benz GLS comes in three forms: AMG Line Premium, AMG Line Premium Plus and AMG Line Premium Plus Executive. 

Mercedes-Benz GLS AMG Line Premium comes with pretty much anything you could ever want, even in a luxury car. Five-zone climate control, keyless go, a sliding panoramic roof, soft-close doors, a powered tailgate, heated front- and rear seats and an electronically deploying towbar are all included as standard.

Upgrading to Mercedes-Benz GLS AMG Line Premium Plus adds massaging front seats and a heated cup holder, along with the rear-seat entertainment system. 

While Mercedes-Benz GLS AMG Line Premium Plus Executive gives you a heated steering wheel and heating for the third-row seats, while the middle row gets massaging seats, electric sun blinds and a heated cup holder.