Mercedes GLS review

There are big cars, there are really big cars, and then there’s the Mercedes GLS. This 5.2-metre long, 2.0-metre wide behemoth is designed to seat seven people in comfort and is the flagship of Mercedes’ extensive SUV range – think of it as an S Class SUV, if you will. 

As far as rivals are concerned, the GLS is closest in concept to the 5.1-metre long BMW X7. However, as a prospective buyer, you might also want to consider (slightly) smaller seven-seaters such as the Audi Q7, Land Rover Discovery and Volvo XC90, or if you only need five seats, the full-fat Range Rover. 

Right now, there’s only one engine on offer for the core GLS: a 3.0-litre six-cylinder diesel that brings a 400d badge. There is, however, a performance-focused Mercedes GLS 63 with a 4.0-litre V8 that is designed to take on the mighty X7 M50i, while the extravagantly luxurious Mercedes-Maybach GLS 600 (which also features the same V8-engine) has its sights set squarely on the Bentayga Bentayga and Rolls Royce Cullinan. 

In the GLS 400d, no matter which of the three trim levels you choose, you get a nine-speed automatic gearbox, four-wheel drive and air suspension as standard. Plus, the interior is finished to the same kind of level as you'll find in the S-Class limousine, and Mercedes also offers semi-autonomous tech to make driving easier and help keep you safe.

You can even specify your GLS with an off-road package if you want to venture off the beaten path – although, let’s face it, cars of this type are rarely asked to tackle more than a slippery National Trust car park. 

In this review, we’ll look at everything from what the Mercedes GLS is like to drive, to how practical it is compared with rivals and how much it will cost you to run. Or, alternatively, to see how much we can save you on a new GLS, check out the deals available through our New Car Buying service.