• Vast exterior dimensions mean enormous interior
• Three rows of seats for most, plus a big boot
• All seats move electrically

With a 60mm longer wheelbase – the distance between the front and rear wheels – than its predecessor, there’s even more space in the GLS’s cavernous interior, most notably for middle-row occupants, as well as those accessing the third row.

Up front there are no complaints, with a vast amount of space to stretch out in. It’s a similar story in the middle row of Benz and AMG versions, with electrically adjustable seats across the bench. Glide these forwards slightly to free up even more room in the third row and it’s possible to get a pair of adults comfortably in the back. This is helped by the tall body and high roofline that stretches the length of the car.

Maybach models are configured differently: there’s no third row of seats as the focus is on making those chauffered in the back even more comfortable. Those seats are set further back than in seven-passenger GLSes and can be reclined further, too. Maybach First Class models have just two very luxurious seats in the back that aren’t far removed from the priciest positions in aircraft.

Is the GLS easy to park?

There’s no escaping just how big this Mercedes is, though. For all it is light and effortless to drive around at low speeds, finding somewhere in a tight car park to both slot it in and then be able to get out will be tricky.

It’s not just its width, of course – don’t be surprised if at least a quarter of your GLS juts out beyond the painted lines of the bay.

Usefully, it’s packed with more camera and sensors than a CCTV emporium, so you get a wide range of audible and visual information about what’s round you. Just be aware that if you’re moving to one of these from al Volvo XC90 or Land Rover Discovery you will need to acclimatise yourself with its size rather quickly.

How big is the boot?

If you need lots of storage, you’re also in luck; the rearmost seats fold flat into the floor, and the seats in the second row fold flat, unlocking a whopping 2,400 litres of storage space – 100 litres more than the previous-generation GLS. You won’t have to faff to get the seats down, either, as all are electrically adjustable and fold away at the press of a button from the boot of the car. You can also lower the air suspension to make it a little more accessible.

With the third row in place, boot space measures at 355 litres; but folded, a vast 890 litres of space is available. There’s a generous amount of extra storage space throughout the car too, with big door bins, a large central storage bin beneath the armrest and no less than three USB ports to keep your devices charged.

Not that you’ll want to be doing a tip run in a Maybach GLS, but it’s worth noting that it’s not as practical as its seven-seater siblings. Boot capacity is limited to a still-generous 465 litres, but the rear seats don’t fold over, so there’s no expanding the space for carrying longer loads. 

If you tow regularly, then also be aware that while Benz and Maybach models can haul up to 3,500kg of braked trailer, the AMG can’t be fitted with a towbar.

How safe is the Mercedes GLS?

• Strong safety credentials in the GLS
• Four Isofix child seat anchors (not Maybach models)
• Plus standard-fit driver assistance pack

Mercedes’ GLS comes with an array of safety equipment, as you’d expect, even in the entry-level GLS 400 d AMG Line Premium specification. Standard features include a Driving Assistance package, parking assistance with a 360-degree camera, an enormous head-up display system and Trailer Manoeuvring Assist.

The Driving Assistance package comprises of:

• Active Blind Spot Assist
• Exit warning function
• Active Braking Assist
• Cornering and Cross-Traffic function
• Congestion emergency braking function
• Active Distance Assist DISTRONIC
• Active Speed Limit Assist
• Extended restart function on motorways
• Route-Based Speed Adjustment with end of tailback function
• Active Lane Keeping Assist
• Active Steering Assist
• Active Lane Changing Assist
• Active Emergency Stop Assist with SOS function
• Emergency lane function
• Evasive Steering Assist
• Pedestrian warning function near pedestrian crossings
• Pre-Safe Plus
• Traffic Sign Assist

More expensive GLS models also feataure additional equipment:

• Active Stop-and-Go Assist
• PRE-SAFE impulse side – moves occupants away from doors just before an imminent side impact

Euro NCAP has yet to put a GLS through its crash-testing programme, but given the related, smaller Mercedes-Benz GLE scored a full five stars, it’s difficult to imagine this wouldn’t achieve the same result.