What is it?
We’re now getting through the range of the fourth-generation Mercedes-Benz GLE (once known as M-Class), which brings us here to the most potent diesel-powered version you can buy.
The GLE 400d uses a 2.9-litre straight-six turbodiesel producing 325bhp and a hefty 516lb ft. You can also get a lower-powered (268bhp) version of this engine in the 350d, plus an entry-level four-cylinder in the 300d with 242bhp. Whatever version you choose, power is sent to all four wheels through a nine-speed automatic gearbox.
Elsewhere, the 400d is much the same as we already know. This new GLE is longer, wider and lower than the car before it and comes with the option of seven seats for the first time. It’s also a technological tour-de-force, with a high-tech, high-quality interior and just one trim 'option': AMG Line.
Yet the GLE’s real party piece that we were so impressed by on its international launch, the clever E-Active suspension – which integrates a development of the Airmatic air suspension with a 48-volt electrical system and camera to scan the road ahead and individually prime each wheel – remains absent from the UK options list and therefore our test car.
What's it like?
What we can marvel at on the GLE, though, is that engine. It’s a really lovely thing, with actual aural character. That’s so lacking in most petrol cars these days, let alone diesels that were never known for their bark, yet the growl from the under the bonnet as you explore the wide band of torque – which is delivered with some considerable shove – will raise a smile. It’s an engine willing to be revved, and one with acceleration that feels better than the official 0-62mph time of 7.6sec suggests.
The engine is ideally suited for towing, too, our GLE coming equipped with the £1150 Towing Package that boosts capacity to a mighty 3500kg. Real-world economy hovered around 30mpg on our mixed-roads test route, which is decent if not outstanding for a big, heavy car, yet the 85-litre fuel tank at least means infrequent fill-ups, thanks to a range of close to 600 miles.
A great engine, then, but not a great car overall. While the primary ride is as about as comfortable as they come, the secondary ride really lets your backside know you’ve been over a bump or a scar in the road surface. It’s the biggest thing that lets the 400d’s mask slip from being a complete, well-rounded, luxurious and comfortable SUV.