Mercedes-Benz GLS review

Big old bus, the GLS. But doesn’t really feel it in the States, where it’s dwarfed by Chevy Suburbans and Ford F-150s.

Much like the S-Class, the focus here is on comfort and refinement, though obviously much effort has been put into masking the GLS’s true size and weight. For example the ‘E-Active Body Control’ suspension, which made its debut on the GLE, keeps the car eerily flat in the bends (or even tilts it in, like the S-Class Coupe) and scans the road ahead so it can prepare itself for upcoming bumps. It can even effectively bounce the car out of trouble off-road (where the GLS is impressively capable), and gives individual control of the car’s ride height at each corner with sliders. It’s an impressive bit of kit, no doubt. And we’re told it will make it to the UK at some point.

Till then, all GLSs destined for British roads get normal air suspension. No bad thing - it’s as good a setup as you’ll find anywhere, albeit lacking the adaptability and body control of the expensive 48-volt E-ABC. For the kind of driving most GLS owners will do it does the job just fine.

This is always a very comfortable car - whatever the suspension, and however big the alloys (they go up to 23-inches), the GLS flows down the road like a big SUV ought to, with a little heave, pitch and roll, but a reassuring weight, solidity and stability. It’s relaxed and unstressed, and a truly superb car in which to do distance, too - very slippy for a big SUV so wind-noise is kept to a minimum, the seats are tremendous and the engines lusty, long-legged and all-but silent.

On engines - Brits only get one. It’s the 3.0-litre straight-six diesel from, well, pretty much every other big Benz you care to mention. We’ve tried it the S-Class, E-Class, G-Class, GLE and probably a few others we’ve forgotten about. And it’s great - powerful, brawny, and even sounds pretty nice when you lean into it. A near-perfect fit. Of course it isn’t a massively fast car, the GLS 400d, but it isn’t bad - 0-62mph takes 6.3 seconds and the top speed is 148mph thanks to 325bhp and 516lb ft.

Those wanting more speed can wait for the straight-six petrol GLS 450, which deploys Merc’s ‘EQ’ mild-hybrid tech’ (362bhp, 369lb ft, 0-62mph in 6.2 seconds, 153mph). No V8 just yet, as we Brits don’t (and won’t) get America’s lovely GLS 580, which uses the familiar 4.0-litre V8 from all AMGs ever, but with the same 48-volt mild-hybrid gubbins as the 450.

Inevitably there will be a proper AMG at some point, which will no doubt have a whopping-great V8 with upwards of 600bhp. A Maybach-badged posh(er) GLS ought to arrive at some point too, though we don’t know what engine that might get.

All engines come with the nine-speed automatic gearbox, which 95 per cent of the time is smooth and quick-reacting, but has a tendency to get a little flustered and out of sync if you demand a sudden birth of acceleration.