Mercedes GL350 BlueTec 4Matic

SUVs account for around one-fifth of Mercedes’ global sales. And while the flagship GL is aimed mainly at US buyers, it’s a worthy rival to the likes of the Audi Q7, Range Rover and Discovery with its blend of comfort, luxury and space. Strong refinement, efficiency and handling are highlights, while the seven-seat layout is versatile. It won’t be cheap, but we’ll have to wait until UK prices and specs are revealed to see if the GL is good value.

Engineers developing the new Mercedes GL had a brief to deliver a large SUV to match the comfort, safety and refinement of an S-Class. Have they succeeded, and created a genuine rival to the forthcoming new Range Rover?

The MkII GL uses the same platform as the original, but the styling has been brought up to date, with a more upright grille, LED running lights and reshaped bumpers giving a similar look to the latest M-Class. The GL is vast, too, at over five metres long.

Some buyers will be put off by these enormous dimensions, but many SUV owners demand the road presence they provide. Plus, the car makes great use of all the space, serving up a family friendly seven-seater layout. The 2-3-2 seating is carried over from the old GL, with the rearmost row offering more room than in a Land Rover Discovery, and the outer seats in the middle row can now be specified to fold forward at the touch of a button. Even in seven-seat mode the boot is a useful size; fold all five rear seats and it offers 2,300 litres of space.

Up front, the dash has been brought into line with other new Mercedes. Top-notch materials, a swish design and a lofty driving position all impress, while tech updates include an optional around view camera for easier parking and Crosswind Assist that uses the ESP to bring the car into line in strong gusts.

Buyers can choose between our GL350 BlueTEC V6 diesel and the GL500 BlueEfficiency V8 petrol. Mercedes claims the diesel uses 20 per cent less fuel than before, while emissions are down 43g/km to 192g/km – even though this car has 47bhp more power and 80Nm more torque, at 255bhp and 620Nm.

The diesel is relaxed and the 7G-Tronic auto gearbox is a good match. It kicks down smoothly and offers decent manual control via the steering paddles. Equally smooth is the stop-start system.

Performance is adequate, but the most striking thing is the engine’s refinement. Smooth power delivery in the mid range ensures it’s responsive and quiet.

Adding to the appeal is the air-suspension, which offers a cushioned ride, while tyre and wind noise is well isolated from the cabin. On motorways the GL is quiet, stable and very relaxing. Considering its size and weight,it also feels quite agile on narrower, twistier roads.

With the optional Active Curve System fitted, adaptive anti-roll bars keep body movement in check and there’s a reassuring level of grip. The electric power-steering is light but positive and accurate, with reasonable feel.

Off-road the GL is equally accomplished, with hill descent control, plus the air-suspension lets you raise the ride height. The optional ON&OFF ROAD package adds more underbody protection, a limited-slip diff, a two-speed transfer case and six switchable off-road programmes. In this trim the GL can cope with a 35-degree tilt angle and wade through water up to 60cm deep.