Mercedes GLS review

The Mercedes GLS is a very heavy car, tipping the scales at almost two and a half tonnes. But thanks to the huge amount of low down grunt generated by that 3.0-litre diesel engine, it builds speed effortlessly; it’ll cover the 0-60mph dash in a swift 6.0sec (recorded at our private test track). However, while you certainly wouldn’t describe that as slow, it’s not as quick as the 5.6sec that the BMW X7 xDrive40d clocked in the same sprint.

As with the X7, there can be a small delay before the GLS’s automatic gearbox responds when you ask for a sudden burst of acceleration. However, this is nowhere near as obvious as it is in some other rivals – we’re looking at you, Audi Q7 – and the GLS’s shifts are suitably smooth most of the time.

Engine refinement also impresses; in fact, it’s easy to forget that you’ve got a diesel under the bonnet. And, while the car’s big tyres generate a bit of road noise, wind noise is very well controlled – especially when you consider the size of the hole that the GLS is punching through the air.

Instead, it’s the way the car rides and handles that disappoints. No matter which mode you select for the air suspension, the GLS tends to wobble about like a jelly on a spin dryer, and this is especially bad news for any passengers prone to travel sickness.

What’s more, it doesn’t exactly glide over bumps and potholes. Not only does the rival X7 offer a more controlled and comfortable ride, but it’s also better at disguising its bulk in corners, combining superior body control with more precise steering.

Like most big SUVs, the GLS will more frequently be seen traversing shopping centre car parks than rocky rural landscapes, but it should be able to cope easily with deep snow and cambered icy surfaces, particularly if you specify the optional Off-Road package, which brings low-range gears and tailored off-road driving modes. That said, if you are planning on venturing off the beaten path on a regular basis, make sure to take a look at the utterly fantastic Land Rover Discovery – what it can do off-road is simply staggering.