This is the all-new GLS, a car that Mercedes has dubbed “the S-Class of SUVs”. The luxury limousine is considered to be the best in the business, so the brand’s latest model has a lot to live up to.
Of course, Mercedes has form when it comes to large luxury SUVs, with its GL and later GLS predecessors, and in many ways this version achieves jacked-up executive-class travel better than any of its ancestors.
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While the previous GLS architecture could be traced back to the 2005 M-Class, the latest model shares a platform with the new GLE. It therefore starts with a lighter, more rigid structure – one that can accommodate the brand’s latest driver-assistance systems and infotainment. It’s grown in size, too; at 5,213mm overall, it’s 83mm longer than the old GLS and 62mm more than the BMW X7.
The dash in the new car is lifted virtually wholesale from the smaller GLE. But while that means it uses the same brilliant twin 12.3-inch MBUX infotainment set-up, we’d hoped for something rather more special.
Arguably, though, the back seats matter more in a car such as this, and here the GLS really hits the spot. There are six or seven-seat layouts to choose from; the former offers two captain’s chairs in the second row, the other a three-person bench. The latter can be enhanced with the optional Rear Comfort Package Plus, in which the centre seat folds down into a large armrest with a removable tablet for controlling the comfort and entertainment functions. It’s also possible to add a pair of 11.6-inch touchscreens to the front seat-backs, so passengers can watch movies and browse the web.
Where the GLS really excels is in the third row. Mercedes claims anyone up to six feet four inches will fit here, so the GLS is easily the roomiest seven-seat SUV you can buy. Seven-up, it offers a 470-litre boot – 144 litres more than the X7. In five-seat mode, space grows to 890 litres, and with all rear seats dropped (at the flick of a switch) there’s a van-like 2,400 litres.
One of the GLS’s real tricks is its advanced E-Active Body Control suspension set-up. Various modes alter the car’s suspension to suit specific conditions. Off-Road mode allows the driver to adjust the ride height of each wheel independently, but it’s the two cameras that scan the road ahead to preload the suspension in order to smooth out bumps that are more impressive.
On the move, this transforms the ride comfort remarkably over and above the standard set-up, which can occasionally thump into large dips and rock from side to side over undulations. The system won’t be offered on UK launch models, but it will make its way here eventually. It’s worth the wait.
It helps through corners as well, to an extent. Not only can the air springs maintain a level setting, but in Curve mode the car can actively lean into the corners. It works well on motorways and fast A-roads, but on twisty sections the system isn’t always able to keep up. In any mode the GLS is composed and stable, rather than thrilling, to drive.
From launch, the UK range has only one engine option: a 325bhp 3.0-litre in-line six-cylinder diesel in the 400 d. This motor delivers its 700Nm slug of torque low down in the rev range, so it’s perfectly suited to hauling the GLS. It’s also remarkably quiet.
Any downsides? Well, the GLS doesn’t have the four-wheel-steering option that is available on its X7 rival, so manoeuvrability at low speeds isn’t all that great. Prices for the GLS start from £73,995 in AMG Line Premium trim, which comes as standard with 22-inch alloy wheels, a 360-degree camera and a panoramic sunroof. The AMG Line Premium Plus costs £5,250 more, adding augmented-reality navigation, massaging climate front seats, plus heated front and rear armrests.