Mercedes-Benz GL-Class Road Test Report

Performance

The GL 320 CDI, with 224bhp and 376lb-ft of torque, will be adequate for all but the most demanding owners. It's hardly sluggish (130mph, 0-60 in 9.5 seconds), and has superb cruising abilities, but it does perhaps lack the monstrous performance to go with what is a monstrous car. The GL 420 CDI's 306bhp engine is good for 0-60mph in 7.2 seconds and has huge torque, peaking at 516lb-ft - and feels every bit as impressive as those numbers suggest. The petrol-engined 388bhp/391lb-ft GL 500 is obscene (unless, of course, you’re behind the wheel). Official figures of 0-62mph in 6.5 seconds and a 149mph top speed give a good idea of exactly how absurdly powerful it is. All versions come with a seven-speed automatic transmission, with a manual sequential shift feature that uses rocker switches on the back of the steering wheel to give the driver more gear selection options.

Ride & Handling

For a beast that weighs nearly two-and-a-half tonnes, the GL acquits itself remarkably well. The speed-sensitive steering responds quickly and accurately to inputs, helping it to adhere to a cornering line without constant adjustment. Airmatic suspension and an Adaptive Damper System (ADS) come as standard in all GL models. In Sport mode, the ADS helps stabilise the GL's body control, but the ride is affected. Comfort mode does exactly what it says on the tin, but you predictably lose some of the body control. The 4Matic permanent four-wheel drive system splits torque 50:50 front to rear, so in tight corners you can feel the front wheels pulling the GL through. Off-road, the GL’s credentials are good enough to allow it to be compared favourably with the Range Rover. So in addition to permanent four-wheel drive, there’s a low-range, limited slip differential that can be locked for really serious terrain.

Build Quality & Reliability

Mercedes has overcome quality hiccups in the last decade, so the GL should have a decent record on reliability. The GL is built in the Mercedes factory in Tuscaloosa, Alabama, which has a decent record of late for build quality. The GL is an extremely complex 4x4, with all the attendant electronic equipment - and Mercedes has had a poor track record with this in the not-so-distant past. However, the company has bucked its ideas up in the last few years, so it should be pretty reliable. In terms of the elements that you can see and touch, the leather used for the seats and to coat the dashboard is soft, supple, well stitched and obviously taken from high-quality sources. Some of the interior detailing in early versions was less than perfect, however, especially in the wood-trimmed versions, but this issue seems to have been overcome now.

Safety & Security

If the GL were involved in a collision, you would want to be in the Mercedes. Deformable sections in the front and rear mean that it should offer good protection to occupants in a crash. The GL is also fitted with the Pre-Safe system, which uses the ABS and ESP sensors to determine if the car is about to crash. If a crash is inevitable, the seatbelts are tightened, the front seats are repositioned and the sunroof is closed. Also available is Neck-Pro, which supports the head against whiplash and, in addition to the standard front airbags, curtain bags are fitted across all three rows of seats. Security on the GL consists of an electronic key with infrared remote control and an immobiliser. A Keyless Go option, which allows the doors and tailgate to be opened without a key and engine-starting with a button, is also available.

Space & Practicality

Surprisingly, the GL isn't as spacious as it looks from the outside and there's little luggage space when the third row of seats is in use. Those third-row seats electrically fold away at the touch of a button, however, which is neat. The middle row bench seats splits 60:40 and can be stowed by folding the bases forward and then dropping the backrests. The result is a huge 2,300 litres of load space: we drove one test car to the French Alps for a self-catering family holiday and managed to get a huge amount of stuff in there. The tailgate can be opened and closed electrically, which will be good news for shorter owners, as it rises very high when open. The front seats are extremely comfortable, even after 12 hours driving. There’s also a sensible and logical control layout, with the Comand infotainment system controllable from steering wheel controls.

Ownership & Value

With prices starting at £52,485 the GL isn’t cheap. Much of the equipment is standard, but if you start adding options such as a DVD system, uprated hi-fi, bigger alloys and better trim, the cost starts going up alarmingly. The GL isn’t cheap to run, either. Official fuel consumption figures start at 29.1mpg for the 320 CDI, rising to 21.2mpg for the V8 petrol version: in the real world, those figures are likely to be a fair bit lower, especially for the 500. CO2 figures of 257g/km to 317g/km also mean that all models are in the top road tax bracket (Band G). Used values for 4x4s have also fallen off a cliff over the course of 2008 – nobody wants the costs and lack of green credentials associated with large SUVs - so don’t expect to see any real money back when you come to sell your GL.