The objections of many to the rise of the 4×4 have been well documented. Dubbed planet-killers and gas-guzzlers, they’ve been the subject of much social hatred and envy attacks.

But is all this hand-wringing warranted? And, more controversially, what would happen if you made a 4×4 with the emissions and fuel economy of an average family car?

For the third generation Mercedes M-Class, that’s just what they’ve achieved.

For the first time, the M-Class is now available with a four-cylinder diesel engine. Badged the ML250 BlueTEC, it’s home to a 2.2-litre turbodiesel that has near-identical power and torque figures to the larger V6 engine used in the previous generation. Peak power of 204hp arrives at 4,200rpm, with maximum torque of 500Nm available from 1,600rpm. It’s this torquey character that helps propel the ML250 to 62mph in 9.0 seconds, on its way to an electronically-limited 130mph top speed.

While that may not sound like rocket-ship performance on paper, in the real world the 250 is more than capable of holding its own in the daily cut-and-thrust.

More surprising, however, is the economy that can be achieved while doing it. The official figures show 44.8mpg on the combined cycle, and during our time with it we discovered that to be not outside the realms of possibility.

CO2 emissions vary depending on wheel choices, but start from just 165 g/km, placing the ML in VED Band G with an annual bill of £175 – the same as a diesel Honda Accord.

Despite the promise of low emissions and good fuel economy, there will still be some who demand a more refined delivery from their engine, and for them, there’s the 3.0-litre V6-engined ML350. With its 258hp and 620Nm of torque, the 350 is undoubtedly the more fun of the two, sprinting to 62mph in a hot hatch-rivalling 7.4 seconds and on to 139mph. The efficiency mantra hasn’t been abandoned in the search for speed, however, and the ML350 will still record 39.2mpg and 189g/km.

Both engines make use of Mercedes’ BlueTEC system, which injects an aqueous urea solution known as AdBlue into the exhaust gas stream. The chemical reaction that follows converts up to 80% of the harmful nitrogen oxides into harmless nitrogen and water.

A second blue filler cap next to the fuel filler leads to the 25-litre AdBlue tank under the boot floor, although topping-up should only be required at service time and will mostly therefore be carried out by the dealer.

Both models are mated to a seven-speed automatic transmission that’s controlled by a steering column-mounted stalk and a pair of paddles behind the steering wheel. The transmission has been modified to accommodate a new start/stop system that cuts the engine when the vehicle comes to a stop.

While generally smooth in operation, there were occasions during our tests when the gearbox was somewhat undecided about which ratio to choose in a given situation, and there was often a subtle but noticeable jolt as the transmission selected a gear after the start/stop system restarted the engine.

We also found the column-mounted stalk to be a bit of a chore when shunting in and out of tight spaces, and there seemed to be an excessive delay between requesting reverse and actually finding it available.

The paddles worked largely as you might expect, but overall we found we missed the more intuitive tiptronic function of the previous generation ML’s console-mounted gear lever.

In place of a gear lever is Mercedes’ rotary controller for the multimedia system. We’re still not a fan of these systems and their bewildering combination of spinning, sliding and clicking that seem so beloved of the German manufacturers. Grabbing your nearest semi-retired company director and assigning them the task of tuning into Radio 2 will yield little more than anguished facial expressions and a series of sticky fingerprints on the centre console’s colour display (no, it’s not a touch screen).

Thankfully, the rest of the interior is much more intelligently thought out. Electric seat adjustment controls are mounted high up on the door, rather than hidden away on the side of the seat, the instruments are clear and fuss-free, and the steering wheel is pleasant to hold and not overloaded with buttons.

There’s plenty of room, too, particularly for heads and elbows, and even rear-seat passengers are well catered for.

Boot space is more generous than either a Porsche Cayenne or BMW X5, with a total of 2,010 litres available with the seats folded flat.

The M-Class retains its trademark hidden D-pillar, with the darkened glass of the tailgate appearing to wrap around to the rear side windows.

The rest of the design has been tweaked for added sporty appeal and, while still unmistakably M-Class, it’s a much tauter shape, with a chiselled, square-jawed look. That said, the rear from some angles can look a little ungainly, but is perhaps more a function of Mercedes’ desire to retain the ML’s boxy practicality.

Big wheels features across the range, with even the most basic models endowed with the full 19-inches.

The standard steel suspension does an admirable job of smoothing out imperfections at low-speeds, more so than the optional air suspension, although pressing on through the corners can initiate a degree of body heave as the weight transfers from one side to the other.

Those intent on using the M-Class as a sports car can specify the Active Curve System (£3,240) in conjunction with the £1,775 adaptively-damped air suspension, and doing so adds active anti-roll bars front and rear that use data from a myriad of sensors to keep the ML’s body flat through the corners.

The electric power steering uses a variable degree of assistance depending on vehicle speed, with maximum assistance available for low-speed parking manoeuvres but reduced assistance at high speeds for improved stability. The variable assistance can take a little getting used to, but the increased ease of arm-twirling at low speeds makes town driving a more relaxed affair.

If you’re compelled to drive into the rough stuff, all MLs feature Mercedes’ 4Matic four wheel-drive system. There’s no low-range transfer case, but a centre differential can apportion up to 70% of the engine’s torque to either front or rear axle, while the 4ETS electronic traction control system can intervene further using brakes on an individual wheel to transfer torque to wherever has the most traction.

An optional On & Off-Road Package adds a two-speed transfer case, skid plates, upgraded air suspension and a Land Rover-style rotary control to select one of six driving modes.

Standard M-Class models have 202mm of ground clearance, but this increases to 285mm with the off-road package, while approach and departure angles of 26° and 25° respectively jump to 31° and 29°. The maximum wading depth also receives a boost from 500mm to 600mm.

Gone are the days that forced any Mercedes purchaser to delve headlong into the options list to equip their vehicle with a long list of goodies in order to preserve residual values. Even the base SE model features satellite navigation (although admittedly it’s the Becker Map Pilot system that plugs into a port in the glovebox), as well as climate control, electric seats, Bluetooth connectivity, rain-sensing wipers and metallic paint. The slightly more aggressively-styled Sport model adds the full Parktronic system, electric tailgate, AMG body kit and AMG alloy wheels.

Ignoring for the moment the £83,655 ML63 AMG, prices for the diesel models start at £43,870 for the ML250 SE, rising to £49,130 for the ML350 AMG Sport. That compares favourably with the BMW X5’s starting price of £47,890 and the Porsche Cayenne Diesel’s £47,390, but if you can sacrifice some of the spec a Land Rover Discovery at £38,850 becomes a tempting proposition.

While the Land Rover has more space and arguably greater 4×4 ability, the Mercedes beats them all when it comes to efficiency, both in terms of fuel economy and CO2 emissions. And, in a country where cars are taxed for breathing, that’s become all the more important.