The M-class' lines have worn so well that the second generation model kept the same sporty stance and raked forward C-pillar but added more pronounced wheelarches and a rising swage line along its flanks. It marked a definite swing towards the sports end of the sports utility market and differentiated the Mercedes nicely from cars like the Land Rover Discovery and the Volkswagen Touareg.
Although the sharply raked back windscreen and contoured body panelling give the M-Class a sporty, compact appearance, the tape measure shows just how artful its stylists have been. It's 150mm longer than its predecessor, 71mm wider and the wheelbase grew by 95mm. It is also 7mm lower. Aerodynamics were improved from a Cd value of 0.39 to 0.34 with fuel economy savings of as much as ten per cent.
The single biggest change that transforms the M-Class is the improved quality of the interior. Gone are the brittle plastics and uninspired ergonomics of the old M-Class, replaced by something that's far more in keeping with Mercedes premium image and pricing. The dashboard features a pair of cowled main dials with a digital information panel between, while the centre console retains the styling of the up-market E-Class models. Although it's not what you'd call packed with surprise and delight features, the cabin now befits a vehicle of this class.
At 880mm, the distance between the front and rear seats is a full 15mm greater than in the old car, achieving a level more akin to a luxury saloon. Despite the additional rear legroom, luggage space goes up. Fold the 63:37 rear bench flat and there's 2050 litres (up by 30l) available. Removable cushions can be ordered as an option, which means that an entirely flat load floor can be attained, stretching 210cm to the back of the vehicle.
Aside from checking the structural integrity of some of the internal fittings, there's not a great deal to worry about with a nearly new M-class. Most premium 4x4s have led relatively pampered lives, as school run is far gentler than black run. Check the underbody and the undersides of the front and rear valances for damage, as the M-Class' modest ground clearance and wheel articulation does not match up to an equivalent Range Rover when the going gets tough.
(approx based on an ML320CDi) M-Class parts prices aren't as expensive as the premium image suggests. Spend a lot of time crawling down muddy slopes and your fun will cost around £90 for a new set of front brake pads. Trying to mount a tricky boulder that destroys a radiator will cost you approximately £350. A more likely scenario is a shopping trolley through a headlight which will wipe around £200 worth of smile from an M-Class owner's face. A new alternator requires alternate plans for £350, and a new starter motor will be around £275.
We'll concentrate here on the mainstream models, starting with the ML320 CDI. Unlike old Mercedes diesels, which were rather lumpy five-cylinder units, this engine is a creamy V6 with four valves per cylinder. Rated at a healthy 224bhp, it's got more than enough muscle to haul the 2110kg Mercedes around. In fact, its torque figure of 510Nm is even beefier than the V8 ML500 version. What's more, you'll reach this figure at little more than tickover and sustain it across a broad plateau from 1,600 and 2,800rpm. The switched on will realise that this makes the ML320CDI an extremely adept tow vehicle. This common rail direct injection engine has quickly proved a winner for the Daimler Chrysler group and it's being plumbed into all manner of Mercedes and Chrysler models to great effect but the M-Class vies with the C-Class for the most attractive vehicle to use the 3.0-litre unit.
Slotted beneath the low-slung bonnet of the M-Class, this engine will punch the car to 60mph in a smidgeon over nine seconds and on to a top speed of 130mph. Combined fuel economy is rated at 30.1mpg which is little short of astounding given the size, weight and performance of the car. With a 95-litre tank, the ML320CDI therefore excels as a long distance cruiser, capable of notching off over 800 miles between refuelling stops. The best petrol alternative is the ML350 which will get to 60mph from rest in just 8.1 seconds and only let up when 134mph is showing on the clocks. A combined fuel consumption figure of 24.6mpg may well be this car's Achilles heel although if you can afford to fuel it, you'll no doubt be grateful for the massive 95-litre fuel tank that allows a serious cruising range between pit stops. With 272bhp on tap, the ML350 is rarely lacking in go and the 350Nm of torque on hand gives it decent overtaking ability. Granted, it's not the 510Nm available in the ML320CDI, but it's enough to be getting on with.
The M-Class has established itself as the sort of luxury 4x4 Mercedes should be making; one that adds lustre to rather than trades on the qualities of the three-pointed star. It's been long overdue but now that we do have the second-generation M Class, it's cemented itself as a decent used buy. The sensible engines make the best picks and a low mileage ML320CDI with metallic paint has to be the plum choice.