Whereas the first generation Mercedes M-Class was never that brilliant, the MK2 car has been a revelation and more than deserves a second chance. Now in revised MK2.5 form, the latest M features a range of great engines, surprisingly crisp road manners and a renewed commitment to build quality.

Never say that Mercedes-Benz is a company too big not to learn a lesson. Back in Spring 1998, it thought it had the market licked with the introduction of the M-Class and so it proved for a short period before it was eclipsed first by BMW's X5 and then by a whole slew of pretenders that queued up to put a lick on the big Merc. Volvo's XC90, Volkswagen's Touareg and Porsche's Cayenne all did it better. Unaccustomed to being schooled in quite such a manner, Mercedes brought us a second generation M-Class in 2005. Bigger, sleeker, more powerful and better built than before, this was quite a response but the market doesn't stand still. Faced with newer, sharper rivals, Mercedes has worked on the M-Class still further, refining some parts, improving perceived quality and giving it even more on the road presence. The German giant isn't going to let the opposition one-up them quite so easily again.

It's not often the case with Mercedes products but the best buy in the M-Class line up might just be the entry level model, the 190bhp ML280 CDI, with the more powerful ML320 CDI derivative nipping at its heels. The latter model features a V6 third-generation common rail unit that's good for 224bhp and 510Nm of torque. Above this is a 302bhp ML420 diesel that'll get to 60mph in just 6.5 seconds. The two mainstream petrol engines are a little more familiar. The 272bhp ML350 opens proceedings and the range-topping M-Class - if you discount the AMG derivative - is the 306bhp ML500. The potent ML63 AMG model features a 510bhp V8 powerplant with a massive 630Nm of torque and can dip below five seconds to 60mph!

"Always one of the best looking luxury 4x4s"

Fitted as standard to every M-Class model is Mercedes' renowned 7G-TRONIC seven-speed automatic transmission. Both the front and rear suspension has been thoroughly revised for this generation M-Class, with a double wishbone front and a multi-link rear arrangement. For those that really want the ultimate in ride quality, Mercedes also offers an Airmatic air suspension system option that teams up with an Adaptive Damping System that adjusts the responses of the shock absorbers according to the situation in hand. There's also an optional off-road biased air suspension option which adds a two-speed transfer case with an off-road ratio, manually or automatically selectable diff locks and a version of Airmatic which raises ground clearance by 110mm to as much as 291mm. This means that the M-Class will now ford water up to two feet deep.

Always one of the best looking luxury 4x4s, the latest M-Class merely tweaks the recipe a little. Those staples of any midlife facelift - lights, bumpers and front grille - have all been given the once over. Roof rails are now standard fit and there's an optional exterior sports pack available. Other than that, it's business as usual on the outside which means you're getting one of the best proportioned of all big 4x4s, keeping the same sporty stance and raked forward C-pillar with the pronounced wheelarches and rising swage line along its flanks. When it was debuted, it marked a definite swing towards the sports end of the sports utility market and differentiates the Mercedes nicely from cars like the Land Rover Discovery and the Volkswagen Touareg.

For all the talk of slick styling and more powerful engines, the single biggest change that has transformed the M-Class' chances has been the improved quality of the interior and the latest car takes quality even more seriously. The dash is trimmed in nappa leather or ARTICO material, with the door cards also finished in ARTICO. The seats have been redesigned for better comfort and support and there's a choice of three different wood finishes for the fascia; burr walnut, bird's eye poplar or anthracite poplar for a more contemporary look. At 880mm, the distance between the front and rear seats is reasonably good and the 63:37 folding rear bench folds flat to access up to 2050 litres of fresh air. 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.

The Mercedes business model has traditionally been to ask a little more than BMW and a fair slug more than Audi for a product that retains a degree of exclusivity and the residual values of which make it a fairly sensible buy. The M-Class is a little different to that template. For a start, model for model, it's not really any dearer than an Audi Q7 and is less pricey than a BMW X5. The entry level ML280 CDI diesels look strong value for money at just over £36,000 which is about what you'd pay for a well-equipped Mitsubishi Shogun diesel. All across the M-Class range, it's possible to find rivals which cost a good deal more and offer less. If you've got £75,000 to spend, the MLK63 AMG offers more power than a Porsche Cayenne Turbo and makes it without recourse to a turbocharger as well. Somewhat counter to preconceptions, it's actually the more entertaining drive.

Yes, it's indulgent and not wholly relevant but the ML63 AMG is a real force of nature. The standard fit wheels are high-sheen 19-inch AMG five-spoke alloys and the ride and handling have been optimised for the 295/45 R19 tyres these wheels wear. Thankfully Mercedes resisted the temptation to bling the ML63 AMG to kingdom come. The styling changes over the ML500 are actually rather subtle, the biggest giveaway probably being the rear apron and exhausts. The wings are slightly flared as well and there's an AMG radiator grille. Stainless steel running boards ruin any vestigial pretence of off-road ability and dark tinted rear lights are also fitted. The interior features AMG sports seats trimmed in Nappa leather and Alcantara. There are also AMG-specific door sills, steering wheel and instrument cluster. Stainless steel sports pedals with rubber grips and a 200mph calibrated speedometer will have school kids drooling.

Mercedes has improved the efficiency of the M-Class' engines but choose a petrol-powered M-Class and you'll still get through quite a sizeable lake of juice over a typical three year ownership stint. Even the entry-level ML350 will sup it at the rate of 24.6mpg and that's on a good day. If you approach 20mpg on a regular basis, you'll be doing very well. During performance testing with the ML63 AMG, we saw 3.9mpg on the car's computer at one point although the stated figure for this car is around 17.5mpg during mixed use. Naturally, the diesels are far better in terms of fuel economy, the ML320 CDI managing just over 30mpg and they also retain their value a lot better when the time comes to sell. A figure of 59% of new price retained after three years is very good for an ML320 CDI, and is a little better than BMW or Audi can manage with the X5 3.0d and the Q7 3.0TDI respectively.

The entry level ML280 CDI is the cheapest of the M-Class models to run, turning in a figure of 77.6 pence per mile over a typical three year ownership period., This steps up to 81.9ppm for the ML320 CDI, 87.5 for the ML350 and 116.2ppm for the ML500. Insurance ranges between group 16 and group 20.

There's a very fine line between resting on one's laurels and not messing with a winning formula, but Mercedes didn't need to do a whole lot to keep the M-Class at or near the top of the tree. It's a fundamentally good vehicle and one that retains a freshness to its styling even without the latest round of revisions. The changes that have been made are worthwhile but don't let the window dressing distract you from the fact that the M-Class gets the basics right.

It's big enough, it's got a great selection of both petrol and diesel engines and it throws up a few surprises. Not too many people realise that the ML280CDI actually competes squarely on price with a Land Rover Discovery or that the ML63 AMG will drive circles around a turbocharged Porsche Cayenne. We have a sneaking suspicion that the M vies with the S-Class as Mercedes' strongest product, and that's serious recommendation.

TOP 5 M CLASS DEALS

The results below show the top M CLASS deals on buyacar

	Mercedes-benz M Class ML320 CDi SE 5dr Tip Auto SW Off Road
	ETR	Mthly £696	Saving £8,122	Price £33,658
	Mercedes-benz M Class ML320 CDi Sport 5dr Tip Auto SW Off Road
	ETR	Mthly £735	Saving £8,422	Price £35,858
	Mercedes-benz M Class ML280 CDi SE 5dr Tip Auto SW Off Road
	ETR	Mthly £654	Saving £7,876	Price £31,854
	Mercedes-benz M Class ML420 CDi SE 5dr Tip Auto SW Off Road
	ETR	Mthly £907	Saving £9,520	Price £43,910
	Mercedes-benz M Class ML500 SE 5dr Tip Auto Station wagon Off Road
	ETR	Mthly £943	Saving £9,520	Price £43,910

typical 11.13% APR

PCP finance quote over 48 months,  10,000 miles pa,  deposit of £1000