The Mercedes M-Class is luxurious and well-equipped. Shame the chassis lets it down on ordinary B-roads

Find Used Mercedes-Benz M-Class 2012-2015 review deals
Offers from our trusted partners on this car and its predecessors...
Used car deals
From £7,500
Sell your car
In partnership with
Powered by

Mercedes announced its intention to make a new large 4x4 in 1990 and formulated plans to develop it with Mitsubishi in 1991. However, the collaboration ended the following year and Mercedes decided to go it alone. But it still took until February 1997 to design and develop the W163 M-Class and build a factory in which to make it, in Tuscaloosa, Alabama.

The original ML was criticised for poor material quality and refinement, and it wasn’t until the Mk2 ML in 2005 that most of those criticisms were addressed.

Four-pot economy and comfort means the ML deserves respect

Years on, Mercedes’ big American gamble is really paying off. Daimler AG’s Alabama factory is established and producing more than 100,000 cars a year, mainly for one of the world’s biggest and most important car markets. And the M-Class luxury 4x4 – the car for which that Tuscaloosa plant was built – is entering its third model cycle.

The ML has reached 1.2 million owners since 1997 and is hailed by its maker as the world’s most popular luxury 4x4. Having tested the water for the likes of the BMW X5, Volvo XC90 and Audi Q7, it’s a more important car than many acknowledge. But arguably more important still are the improvements that Mercedes has made to the M-Class over the generations.

Promising market-leading quality, safety, refinement and efficiency, the new ML seems almost unrecognisable from the rough and ready original. It has developed far beyond an initial early 1990s brief to replace the tough but antiquated Geländewagen and this time, for the first time, is offered with a four-cylinder diesel engine that promises to open up proper luxury SUV ownership to a wider audience.

Back to top


Mercedes-Benz M-Class front grille

There’s a welcome dose of pragmatism and maturity about the new Mercedes ML 250 Bluetec. Higher up in the M-Class range, you can buy versions of the car loaded with state-of-the-art chassis technology to enhance both on-road and off-road performance.

Height-adjustable air suspension and lockable inter-axle differentials are the usual SUV fare. Adaptive damping and active anti-roll bars most certainly aren’t. The ML 250 Bluetec is cast more simply than its range mates as the frugal, refined, spacious and classy old-school family Mercedes to effortlessly meet your every real-world need.

The M-Class has come a long way since the early days of poor refinement and cabin quality

The ML’s most distinctive frontal feature is the big star set among a pleasing new grille treatment. A chrome strip, designed to increase the premium look runs along the bottom of the front bumper. It works, but will be less convincing if you scuff the front by running out of approach angle.

Reflecting British buyers' penchant for large wheels on their large SUVs, no wheels measure less than 19 inches across. Those looking to make more of a statement can choose rims up to 21 inches as an option. 

The M-Class has the reversed C-pillar, which has been a staple feature of the model since its introduction. The D-pillar is, once more, hidden behind the glass to reduce the visible effect of bulk around the back end. A three-piece spoiler is fitted as standard to smooth airflow and reduce drag.


Mercedes-Benz M-Class dashboard

There was a time when large SUVs were graded on their ability to haul heavy loads over treacherous mountain passes or traverse deserts without succumbing to the elements. Now, they’re built to be seamless, silent, cavernous carriages for the social and domestic pleasure of the middle class, and the Mercedes M-Class is no different. This means that, inside, they must exude an ambience worthy of Blohm & Voss.

Despite representing the entry-level M-Class experience, the ML 250 gets the lifestyle trick about right. It lacks the aloof, art deco spectacle of a Range Rover and the implied sportiness of a Porsche Cayenne, but Mercedes’ solemn architecture and sober colour schemes make the ML purposeful enough to compete.

The column stalks are a replacement for ones that feel like they’ve been around for an age. The left-hand one covers the wipers, high beam and indicators

The switchgear’s familiar DNA has also been scaled up to SUV size rather well, helped no end by a dashboard that bulges with broad-shouldered presence and attractive trim stitching.

Doubtless, the three-pointed star on a particularly splendid steering wheel helps to put you in the right egotistical frame of mind, and the front seats’ endless adjustability ensures that the driver can choose between perching in the crow’s nest or hunkering down.

There’s 34mm more elbow room up front, but with one arm habitually perched on the elevated centre console, it’s the 25mm increase in the rear that is probably of more use. Mercedes doesn’t equip the ML with a properly formed centre seat, but there’s still plenty of room to play taxi to a third rear passenger.

Plenty of room for luggage, too: the boot is bigger than a Cayenne’s or an X5’s, and with the seats lowered to reveal 2010 litres of floor-to-ceiling space, its clutter capacity is only eclipsed by the Range Rover Sport and Audi Q7.


Mercedes-Benz M-Class rear quarter

Although it sounds like a utilitarian throwback to find the Mercedes' 2.1-litre, four-cylinder engine in a car like this, it shouldn’t, given the capability of the ML 250

Its 93bhp per litre isn’t uncommon by modern diesel standards, but it still takes some getting used to for those of us who remember (and it wasn’t so long ago) when 100bhp per litre was considered at the sharp end for naturally aspirated petrol cars. 

A urea solution called AdBlue is injected into the exhaust gas to cut NOx emissions by up to 80 per cent

But the 201bhp peak isn’t only what makes this 2.1-litre engine sufficient in the 2310kg (as tested) ML; it’s also the exceptional 369lb ft of torque, a broad spread of it, and the ability of the seven-speed auto ’box to make the most of the power and torque delivery.

It still leaves the ML 250 looking a touch malnourished compared with some of its bigger-engined rivals, but it would be churlish to suggest that an 8.8sec 0-60mph dash in a car like this is insufficient. 

In-gear flexibility is decent if you hold on to the gearbox’s ratios via its steering wheel paddles; 50-70mph in seventh, for example, takes a respectable time of 11.0sec. But even with the gearbox thus selected, you can kick past holding on to a ratio if you’re determined to give the carpet a hard time. Flat out through the gears, the same 50-70mph benchmark can be achieved in a sprightly 5.8sec.

The real benefit, though, is felt at the fuel pump . In our experience, no other SUV of this size and performance will deliver overall economy into the mid-30s.

So it’s quick enough and enviably economical. Why would you pick a bigger-engined M-Class?

Because all things being equal, a four-pot will not be as smooth as a six-cylinder unit from the same manufacturer. The ML 250’s noise levels are more than acceptable, but an unmistakable muted grumble can be heard; there’s no denying that the six-pot ML 350 offers a more hushed environment.

That model shaves around 1.5sec off the 0-62mph time and adds 9mph to the top end, meaning flat out the big-engined ML will reach 139mph. Our European drive of the ML350 indicated the demonstrable benefits of six cylinders; the work performed by Mercedes in reducing NVH and increasing refinement is brought to the fore with a smoother powerplant.

At the opposite end of the ML range and performance spectrum, the ML 63 AMG offers fearsome performance from its bi-turbo 5.5-litre V8. Its 518bhp fires the 2345kg ML from 0-60mph in less than five seconds. Moreover, its prodigious torque reserves (516lb ft) are available through such a broad rev range (1750-5500rpm) that overtaking is a very easy task.



Mercedes-Benz M-Class rear cornering

Mercedes seems to have veered off the dynamism beam, so often found in SUVs like the X5, and the ML is no worse for it. Evidently, Mercedes thinks that not everyone wants an SUV that hopes to display hot hatch levels of keenness.

The M-Class, then, rolls on standard coil springs (as on most rivals bar the standard air-suspended Range Rover Sport) with a relaxed, loping gait. Body control is looser than you’ll find in a Porsche Cayenne or X5 but, by contrast, rolling comfort is superior. There’s little wind and road noise (which actually serves to make the engine’s occasional grumble all the more noticeable), and at low speeds the ML steers with surprising lightness

Ask a lot of the M-Class’s chassis and it will display a lazy kind of response that you’d expect

That’s down to a variable-assistance steering set-up that loses its appealing low-speed oiliness as speeds rise, ostensibly filling the gap with a less assisted, heavier feel that’s meant to promote straight-line stability. 

What it does in practice is to give the M-Class a slightly inconsistent theme: a light-steering, relatively easy-going SUV at lower speeds, but one that becomes a less willing and, crucially, less relaxed companion as its pace increases. 

It doesn’t help that the ML feels its weight if you decide to press on a bit. Do so and the car heaves over on to its springs as it displays a lack of agility that would be fine if accompanied by easy-going steering but is curiously unsatisfying with a heavier set-up. No, best to stick with what the ML does best: let it roll, easily and calmly, and don’t upset the balance.

That is, unless, you’re piloting the ML63 AMG. Here, the active anti-roll bars and ‘Active Curve System’ transform the soft base ML into a responsive, grippy and composed performance car. It seemingly refuses to pitch, roll or dive.


Mercedes-Benz M-Class

The Mercedes ML 250’s price places it shoulder to shoulder with entry-level versions of all of its main competitors. It’s a formidable list: the Range Rover Sport, Porsche Cayenne and BMW X5 all feature in it, and they each come with superior performance thanks to the 3.0-litre diesel engines that prop up their respective ranges. Of course, this issue is addressed by the ML 350 CDI, which matches its equivalent 3.0 TDI rivals for power and torque.

The ML 250’s predictable trump card is the fuel efficiency derived from its comparative lack of cylinders.

Avoid the really expensive options that won’t retain value, such as a TV or the more pricey entertainment units. But do try an ML on air springs if you can.

With 44.8mpg claimed (we achieved 40.9mpg on our touring run), it is the class leader, and if you choose to have the optional 93-litre tank fitted, Mercedes reckons that you could clock up as many as 930 miles between refills.  

Although that’s doubtlessly a little optimistic, the CO2 emissions are laid out in irrefutable black and white and they, too, place the ML 250 out in front of the field. At 165g/km, it finds itself in VED band G, three better than its J-banded rivals. Clearly, that represents a significant annual saving, but from the point of view of showroom tax it also means that putting a Mercedes on the drive is fractionally cheaper than the alternatives.

Of course, choosing the ML 350, and you'll gain two more cylinders and an additional 844cc with predictable results. Mercedes claims an official fuel consumption figure of 39.2mpg - 5.6mpg less than the ML 250. Road tax jumps from band G to band J. And given the relatively small performance differential, we can't understand why you'd plump for the larger engine.

Opting for the ML63 AMG predictably has a catastrophic effect on running costs. It’s claimed MPG isn’t far off half that of the ML 250’s at 23.9mpg, and it emits 276g/km of C02. Still, if you can afford the flagship's £82,995, you should have the resources to keep it running.


4 star Mercedes-Benz M-Class

Are you an enthusiast who likes the occasional spirited on-road drive and whose only car is a large SUV? Then the Mercedes M-Class probably isn’t for you.

But for those who like to dedicate a car to its more conventional use, the M-Class in general, and this one in particular, could be the answer.

The nav’s map screen allows a variety of viewing options: north up, direction of travel up, or 3D direction view. Enough to suit all mindsets

The latest ML is extremely relaxing to drive in an unspirited fashion. It rides comfortably, has a pleasingly solid-feeling cabin and boasts an enviably long range, thanks to the four-cylinder diesel’s economy advantage of 10mpg compared with the V6.

All of our testers decided that it was fast enough, too. All of which means you should be willing to overlook any relative lack of refinement from this engine.

Throw in its excellent running costs compared with its competitors and the ML, in 250 Bluetec form, is as compelling as it has ever been.

Matt Prior

Matt Prior
Title: Editor-at-large

Matt is Autocar’s lead features writer and presenter, is the main face of Autocar’s YouTube channel, presents the My Week In Cars podcast and has written his weekly column, Tester’s Notes, since 2013.

Matt is an automotive engineer who has been writing and talking about cars since 1997. He joined Autocar in 2005 as deputy road test editor, prior to which he was road test editor and world rally editor for Channel 4’s automotive website, 4Car. 

Into all things engineering and automotive from any era, Matt is as comfortable regularly contributing to sibling titles Move Electric and Classic & Sports Car as he is writing for Autocar. He has a racing licence, and some malfunctioning classic cars and motorbikes. 

Mercedes-Benz M-Class 2012-2015 First drives