£69,860 - £103,100 Price range
23 - 37 MPG
Unlike all-new rivals including the Audi Q7, Volvo XC90 and upcoming Land Rover Discovery 5, the Mercedes GLS is a heavily facelifted version of an older car, the GL. It sits atop Mercedes’ refreshed SUV line-up ahead of the mid-sized GLE, smaller GLC and compact GLA.
In a class dominated by luxury interiors and clever technology, its ageing underpinnings put the GLS at a distinct disadvantage. This is immediately apparent when you see the boxy exterior and button-laden dashboard.
While the GLS has its weaknesses, it has plenty of strengths, too. The interior – or more accurately, the space it offers – is very impressive. There’s room to fit seven adults comfortably and enough left over to hold some luggage as well. Factor in the car’s huge 3,500kg towing capacity and the GLS starts to make sense if you have a large family or will regularly use the car for towing heavy loads.
Engine options are limited – buyers can choose from the verging-on-ridiculous petrol GLS 63 AMG, which comes with a twin-turbocharged 5.5-litre V8 (capable of launching the SUV from 0-62mph in just 4.6 seconds) or the far more sensible 350d diesel. It might not have the range topper’s performance but it combines respectable power with affordable fuel economy making it the model we’d recommend.
The GLS gets two trim levels – cheaper AMG Line or top-of-the range Designo Line. Even the basic car comes with a long list of equipment including keyless entry, an upgraded stereo, air suspension and 21-inch alloy wheels.
By modern standards, the GLS’s dashboard features a square and uncompromising shape – something no amount of wood, leather and metal trim can hide. While the Volvo XC90 and Audi Q7 have remarkably simple layouts for what are very complex machines, GLS drivers are faced with lots of buttons that can take some time to navigate.
Mercedes has made a decent go of improving things over the old GL – the GLS gets a new eight-inch infotainment system display controlled by the company’s latest generation touchpad. The steering wheel is also new but, if you expect this to convert the GLS into something of an all-terrain S-Class, you’re in for a shock – the GLS doesn’t feel as elegant as the limo.
Mercedes GLS passenger space
While the GLS’s interior does little to excite your eyes, the rest of your body will be very pleased indeed. That’s because the space the GLS offers really has to be experienced to believed. Unlike the Q7 which has a rather small pair of seats in the boot, the GLS can carry seven adults in complete comfort.
The old-school body shape has its own virtues, delivering the ‘commanding’ driving position that makes SUVs so popular with buyers. Getting a comfy driving position is easy too thanks to electrically adjustable seats.
Mercedes GLS boot space
Loading the GLS with passengers doesn’t leave you with a pitiful boot. Even with all seven seats occupied, the GLS has a 295-litre load bay – that’s not huge, but is enough to stow away the spoils of a shopping trip without needing a return journey.
Dispense with the rear-most seats – which glide into the floor electrically – and the load bay swells to 680 litres and with all the rear seats down full capacity sits at a cavernous 2,300 litres. Perhaps even more impressive is the GLS’ maximum payload of 815kg meaning you’ll need a forklift to load some of the items the Mercedes is capable of carrying.
Further confirming the GLS’ seemingly endless practicality is the 3,500kg maximum pulling ability and air suspension that means the SUV rides flat and true when towing.
The GLS isn’t aimed at people who like their SUVs with a sporty drive – the BMW X5 and Porsche Cayenne cater for them much better. Despite its softer setup, the Mercedes feels more planted in corners than you might expect.
The air suspension has been retuned to do a better job of reining in body lean, but not at the expense of ride comfort. The kind of comical roll you got from SUVs of old is thankfully absent in the GLS’s driving experience and quick curves can be tackled without intimidation.
Specify the top-of-the-range Designo Line model and you also get Active Curve. Borrowed from the S-Class saloon, it has active roll bars that stiffen and loosen to keep body control in check or enhance the car’s ride comfort.
The steering also helps, with enough weight to dial out edginess on the motorway, while being accurate enough to let you hustle the car through bends.
Also revised is the car’s nine-speed automatic gearbox. Testers report it changes gears like all the best do, with a near-telepathic understanding of what gear you are looking for at any one time.
Few will be brave enough to expose their £70,000 SUV to the rigours of off-roading, but all models have four-wheel drive and should cope well with snow-covered roads, muddy fields or sodden motorways. If you are planning on leaving the carriageway, you’d be well advised to go for the £1,985 off-road pack. It adds 100mm of ground clearance, a low-range gearbox for slow and steady progress, and a locking centre differential that keeps all four-wheels spinning for excellent traction.
While the range-topping GLS 63 AMG’s V8 engine might offer blistering performance figures, the car’s astronomical runnings costs are likely to put the vast majority of people off.
It makes little sense because the 350d’s 3.0-litre V6 offers all the performance you’re likely to need in a car of this type. It produces 258hp and, more importantly, a huge 457Ib ft of torque which it brandishes almost from rest. As a result, you’ll hardly notice whether the car is fully laden or towing and the wave of torque can carry the GLS from 0-62mph in just 7.8 seconds and keep on going to an unnerving top speed of 137mph.
While it’d take a seasoned spin doctor to successfully argue the GLS is cheap to run, fuel economy of 37.2mpg really isn’t that bad for such a large car. In comparison, a Land Rover Discovery will return 33.2mpg at best and is nearly two seconds slower to 62mph from a standstill. The Mercedes also betters the Land Rover for CO2 emissions, posting a figure of 199g/km (for annual road tax of £265) next to the Discovery’s 203g/km figure.
Safety body Euro NCAP has yet to test the GLS’s safety, and may never do because it tends to evaluate more popular models.
Older cars tend to perform worse in collisions, which puts the GLS at a disadvantage next to newer rivals, but the car’s standard safety kit is hard to argue with. All models come with a blind spot warning system, lane assist, nine airbags and attention assist that can detect when the driver is tired and warn them to take a break.
You’d have to feel sorry for any pedestrian that found themselves in front of a GLS at full speed, but even they are catered for with an active bonnet that springs up to protect them (to a certain extent) from the hard engine underneath.
The standard equipment list is almost as endless as the GLS’s dimensions. Here’s a breakdown of how each trim is specified.
Mercedes GLS AMG Line
AMG Line represents the cheapest way to enter GLS ownership, but it’s anything but sparse. On the outside, there’s an AMG body kit, with aluminium running boards and 21-inch alloy wheels shielding ‘Mercedes-Benz’ branded brake callipers. The interior kit list is as long as your arm, too, and includes active cruise control, park assist with a 360-degree camera, climate control, a panoramic sunroof, surround-sound Harman Kardon stereo, lane keep assist and a blind spot warning system.
Mercedes GLS Designo Line
Top-of-the-range Designo Line trim adds to the standard car’s purposeful exterior with flared wheel arches and 21-inch inch multi-spoke AMG wheels. Inside, there’s soft Nappa leather with diamond stitching and front seats that are both heated and cooled, and offer four-way electrical lumbar adjustment. The doors close themselves with the faintest of pulls, and passengers in the rear get electrically operated roller blinds and their own climate controls even for those in the rearmost seats.
On the face of it, the Mercedes GLS may look like a jazzed up GL aiming to steal you away from the more accomplished competition. For those after a premium badge and a massive interior, however, it makes a lot of sense. While it isn’t as exciting as rival cabins, the sheer space on offer makes the GLS look like a very tempting option indeed.
The drive is stately rather than sporty so the GLS makes a better case for itself as a comfortable cruiser with decent economy rather than a sporty SUV. In fact, if you’re looking for something akin to a premium badged MPV with off-road prowess, few cars offer the capabilities of the GLS.