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Used test: BMW X7 vs Mercedes GLS

Big and brash, the BMW X7 and Mercedes GLS make no effort to hide their opulence, but which makes the most sense when bought used?...

BMW X7 vs Mercedes GLS

The Contenders

BMW X7 xDrive40d M Sport

List price when new £79,010
Price today £72,000*
Available from 2019-present

The X7 is cheaper than its rival, but is it any less plush and premium?

Mercedes-Benz GLS 400d 4Matic AMG Line Premium Plus Executive

List price when new £99,370
Price today £80,000*
Available from 2019-present

With lashings of tech and a yacht-esque interior, the GLS is a limo on stilts 

*Price today is based on a 2019 model with average mileage and full service history, correct at time of writing

Large often means expensive. If you're flying, more space requires upgrading your ticket, or if you're TV shopping, you pay a premium for a bigger screen. Couple that with luxury – perhaps you'd like champagne on your flight or 4K resolution – and you better have deep pockets. 

It's the same with luxury SUVs. Two of the largest and most luxurious offerings are the BMW X7 and the Mercedes GLS, and both cost the same as a small apartment from new.

BMW X7 2021 rear

Fortunately, the used car market yields discounts. It won't make them cheap as chips, but these two might just enter your budget at three years old. At that point, it's just a question of which opulent high-rider you should buy – and that's why we're testing the X7 and GLS head to head. 

Read on to find out which luxury SUV comes out on top. 


Performance, ride, handling, refinement

These big and heavy four-wheel-drive beasts both have powerful 3.0-litre six-cylinder diesel engines, so neither car is slow. In a 0-60mph sprint, the 335bhp X7 clocked a hot-hatch-baiting time of 5.6sec, with the 325bhp GLS close behind at 6.0sec. Neither has any trouble with country road overtakes – even when heavily laden – and both have a smooth yet punchy power delivery.

Mercedes GLS 2021 rear

There’s a difference in their gearboxes, though. In the GLS, if you plant your right foot on the move, the nine-speed automatic ’box dithers around a little. By comparison, the X7’s eight-speeder is snappier and more assured in its shifts.

The X7’s brakes are better too – it needs almost three metres less than the GLS to bring you to a stop from 70mph.

You’ll also find the X7’s engine more hushed. It’s eerily quiet when you’re pottering around town and wonderfully silky when you’re accelerating up to motorway speeds. The mild-hybrid electrical assistance helps its engine cut out and restart very smoothly in stop-start traffic. The GLS’s engine has no such technology, and while smooth for the most part, it’s a little gruffer and more vocal at low revs.

BMW X7 2021 side

At motorway speeds, though, both cars are impressively refined. Their engines fade into barely audible background noise, while wind and road roar are extremely well suppressed. You’ll feel pleasantly isolated from the outside world, ready to munch through the miles with ease.

This serene tranquillity is more readily broken in the GLS. When you drive over a speed bump or pothole, you hear plenty of abrupt thumps as the suspension bears the impacts. Meet the same obstacles in the X7 and it shields you from those noises rather more efficiently.

In fact, you’ll feel the difference as well as hear it. Although both cars ride on adaptive air suspension, the GLS is far more easily unsettled by surface imperfections, not helped by the enormous 23in wheels it wears as standard. It struggles to smooth out vertical movements when you encounter an undulating road too.

Mercedes GLS 2021 side

The X7 does a much better job of absorbing bumps and crests, and glides over all but the most pockmarked of road surfaces. It also has tighter body control, helping to prevent you from being tossed around in your seat, as well as keeping the car more upright through corners. There’s masses of grip, and while it’s no sports car, it’s more satisfying than the GLS to hustle along a winding country road.

The GLS, by contrast, is far from confidence-inspiring to drive quickly. While the X7’s steering is sharp and responsive, the GLS’s is vague and slow. Plus, the GLS can’t deal with quick changes in direction with the fluency exhibited by the X7.

The X7 has another trick up its sleeve in the form of optional four-wheel steering. When you're driving slowly, it turns the rear wheels in the opposite direction to the fronts to tighten the turning circle. That make it remarkably easy to manoeuvre at low speeds for a car of its size.