Mercedes M-Class (2005-) Review

On the road

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Here's where Mercedes-Benz promises major gains, thanks mainly to the stiffer, unitary body - which, incidentally, helps this M-Class weigh about 50kg less than the old one. There's no doubt that it clings well to the road, but if you're expecting the responsiveness of an X5 or even a new Discovery you'll be disappointed. The steering is soft and rubbery, and you're always aware of controlling a large and tall mass even if it never threatens to fall over. The V8-engined ML500 has enough torque to liven up the cornering experience, with the tail hunkering down as you power out of a corner despite the nominal 50-50 front-rear torque split, but that's as exciting as it gets. The brakes on all versions are soft and springy underfoot, too, although they stop the M-Class effectively enough.

Where it pulls back points is in the ride, which is fair for an off-roader in normal coil-sprung guise (lumpy surfaces do set up a choppy motion, though) and extremely good with air suspension. That's definitely an option worth having.

With the electric seat option you can create a fair driving position, but if you're short in the leg you'll find the pedals too vertical to be able to attack them comfortably. This problem is worse with manual seats, because you can't find an optimum combination of seat height and cushion angle and the front edge of the cushion digs in the back of your knees. Some of the M-Class's slighter, female buyers may not find this a comfortable car. There's a good view out, though, and the instruments and switchgear are clear and logical to use - even the dozens of buttons that make up the optional COMAND sat-nav and telematics system, which is still easier to use than a BMW iDrive.

Off-road, this M-Class copes better than the previous one thanks to that Downhill Speed Regulation, which goes one better than Land Rover's Hill Descent Control by letting you adjust your maximum, ABS-controlled downhill speed via the cruise control. Pressing a button alters the ABS settings for off-road use, and there's a Start-Off Assist to stop you rolling back. With Off-Road Pro, you can raise the ground clearance to 291mm and splash through two feet (600mm) of water. Low range gears are selected on a dial, as are the centre and rear differential locks although the traction systems, which use ABS sensors to brake a spinning wheel, are usually enough. An Off-Road Pro M-Class can cope with as much as the best proper 4x4s, but the normally smooth ride becomes jerky when the suspension is raised.

Hefty 4x4s need hefty amounts of torque to get them going, and with that in mind the ML350, with 258lb ft on tap, is the most disadvantaged of the M-Classes. By normal standards such pulling power should be plenty, but this engine turns out to be the one that hunts the most up and down the seven-speed autobox that's standard fare across the range. It's not a particularly sweet engine when worked hard, either, although its ultimate pace is impressive if you make the effort: 0-62mph in 8.4sec, a top speed of 140mph.

Maybe, then, the more expensive ML500, with 339lb ft, would be better. The figures suggest so - 150mph and 6.9sec to 62mph, which are going some for a 4x4, and the pace is delivered in a much more relaxed fashion with a fine V8 beat when you're pressing on. But there's no need to go the V8 route for a relaxed yet brisk drive, unless you're rich enough both to buy the car and pay for the fuel. Better to drive the ML320 CDI, with a massive 376lb ft of torque, an adequate 134mph top speed and an 8.6sec 0-62 time. It may be slower than the ML350 on paper, but on real roads it's more responsive, quieter and more satisfying. This is a great diesel engine, smooth, refined and keen to respond.

The so-called 7G-Tronic transmission, activated by a rather retro steering-column lever, isn't ideal, though. There's a big gap between fourth and fifth, then the last three gear ratios are so close together as to defeat the point of having so many gears. You can select the gears manually using one of a pair of switches on the back of the steering wheel spokes, but their horizontal action is illogical. Also, when you think you've selected, say, third gear, you've really selected a range from first to third so the 'box will still shift unbidden. After a while you just leave the auto to its own devices. Strangely, you get a 'sport' mode only if you order the Off-Road Pro pack.