The GLS’ sheer size might be a little daunting but its light controls make it surprisingly easy to drive around town – just don’t expect it to be cheap to run
The standard GLS comes with just one engine – a 3.0-litre diesel V6 that produces 258hp. Mercedes claims it’ll return 37.2mpg but, even with a light touch on the accelerator, you can expect to see a figure in the high twenties.
Unlike some diesel engines, it’s very smooth – even when you accelerate hard – and powerful enough to push the vast GLS from 0-62mph in a very respectable 7.8 seconds. The standard-fit nine-speed automatic gearbox is responsive and smooth – slushing gears together nicely when you’re cruising around town but it does occasionally pause before changing down, so you have to wait a second to get full acceleration.
It’s no S-Class but the GLS is impressively comfortable over rough roads and it can accelerate faster than most sports cars – well, in GLS 63 guise at least
All GLS models come with four-wheel drive as standard which helps make it an excellent tow car. It can pull trailers weighing up to 3,500kg, putting it on a level pegging with the Land Rover Discovery and an impressive 700kg ahead of the 3.0-litre diesel Audi Q7.
If you’re after sports-car performance in a seven-seater SUV package, the AMG-tuned GLS 63 is the only way to go. It’ll set you back more than £104,000 but its twin-turbo 5.5-litre V8 produces a colossal 585hp – enough to sprint this 3.2-ton SUV from 0-62mph in just 4.6 seconds. To put that into perspective, that’s as fast as a Porsche 911 Carrera sports car.
The GLS’ sheer size might be a little intimidating at first but its light controls and excellent visibility mean it isn’t too difficult to drive on country roads. The pillars between the front doors and the windscreen can create some slightly awkward blind spots at junctions but the GLS’ huge side windows and wide rear windscreen give you excellent rear visibility.
It’s a little nerve-wracking to drive in town but all models come with parking sensors as standard to help you avoid low-speed scrapes. You even get a 360-degree camera system that displays a bird’s-eye view of the car and your surroundings on the infotainment screen. This is especially useful when you’re faced with some particularly tight width restrictors.
All models come with a clever air suspension system that separates you from the road with a cushion of pressurised air. It helps the GLS soften the blow of monster potholes around town impressively well. Pick the optional 22-inch alloy wheels and you’ll feel a few more thuds through your seat on bumpy roads but the GLS is still one of the most comfortable seven-seat SUVs on sale.
Its soft air suspension and light controls mean it doesn’t feel quite as at home on a twisty country road as the Audi Q7 but the Mercedes is a better bet if you do lots of motorway miles. You’ll barely hear any wind noise or tyre roar in the GLS and it comes with cruise control, lane keeping assist and blind spot warning as standard.
You also get Steer Control that’ll apply the brakes to keep the car stable if the tyres start to slip and automatic emergency braking that helps stop the car quickly if it detects an obstacle ahead. Euro NCAP hasn’t crash tested the GLS but these features – and its sheer size – help make it a very safe seven-seater SUV.
For even greater peace of mind, you’ll want to pick the Driving Assistance pack. It’ll set you back £1,695 but it comes with cross-traffic assist to help prevent you pulling out of perpendicular parking spaces into oncoming traffic and adaptive cruise control to maintain a safe distance to cars ahead before returning to a preset speed when the road’s clear.