"With great diesel engines, a classy image and top build quality, the Mercedes-Benz M-Class is a fine upmarket 4x4."
The Mercedes M-Class is a prestigious 4x4 that's very well built, has a great range of engines and a beautifully designed interior. Pricing is on a par with established rivals like the BMW X5 and Range Rover Sport, while refinement is excellent and there's plenty of space inside. The high driving position means that visibility is great, and road and wind noise is limited. It's a large 4x4, but the M-Class isn't much of an off-roader, so don't expect it to beat a Land Rover in that respect.
There are three diesel engines to choose from - a pair of 3.0-litre versions with 201bhp and 228bhp and a 4.0-litre with 302bhp. Each one has more than enough power and delivers smooth acceleration, but the entry-level 3.0-litre will be sufficient for most owners. Two very powerful petrol engines are available for enthusiasts - a 5.5-litre V8 with 382bhp and a top-of-the-range 510bhp 6.3-litre V8 ML 63 AMG. They're both incredibly fast but are expensive to run. The M-Class handles corners well and has accurate steering, but it's geared more towards comfort than sporty driving, so it's not quite as good to drive as a BMW X5 or Porsche Cayenne.
There's little wind or road noise, and even the diesel engines are exceptionally quiet all the time. The high driving position means that visibility is excellent. The ride is very comfortable and the M-Class only becomes unsettled on very rough surfaces. Passenger space is excellent, both in the front and the back.
Five Euro NCAP stars for adult occupant protection, three for children and one for pedestrians is respectable, but the Q7 looks after children and pedestrians better. Double front, side and curtain airbags are standard, along with anti-whiplash headrests, seat belt pre-tensioners, electronic stability control, anti-lock brakes and anti-skid control. Build quality is excellent and the interior is luxurious, but there are one or two low quality plastics lower down in the cabin, which lets the M-Class down a little. The M-Class doesn't sell in sufficient numbers to appear in Driver Power Reliability surveys, but Mercedes-Benz finished fourth overall in the 2010 JD Power Satisfaction survey, which is very impressive.
The 833-litre boot is bigger than you’ll find in a BMW X5, or even the vast Audi Q7, and if you fold the rear seats flat there's a massive 2,050 litres on offer. Only the Range Rover Sport offers more room. The appeal of the M-Class is limited by the fact that it doesn't have seven seats though. There's plenty of leg and headroom for front and rear passengers, while the large glovebox usefully houses the CD auto-changer.
Value for money
List prices make the M-Class look quite expensive. It's certainly not cheap, but it's priced competitively with its main rivals like the BMW X5 and Porsche Cayenne. Entry-level ML 320 and ML 350 models are well equipped with heated door mirrors, electric windows, climate control, cruise control, front and rear parking sensors, an electrically operated tailgate, automatic wipers and Bluetooth phone connectivity. Sport versions add 19-inch alloy wheels, metallic paint, chrome and steel detailing, sports seats and special leather trim.
Large engines and fuel-sapping automatic gearboxes mean that even the diesel-engined M-Classes are quite expensive to run. The most frugal version is the ML 300 CDI with 32.5mpg and 230g/km, but even that costs £425 per year in Road Tax. The ML 450 CDI with its 4.0-litre diesel engine returns only 26.6mpg and emits 279g/km, so Road Tax is in the top band and costs an additional £10 per year. The V8 petrol ML 500 averages only 21.6mpg and has emissions of 304g/km, while the ML 63 AMG offers only 17.1mpg and a very high 392g/km.