You cannot move for all the new eco-friendly models that are flooding the market right now. Boasting low CO2 ratings and impressive fuel economy figures, it is clear manufacturers have finally got their collective acts together.

One obvious target for criticism by the green brigade has been the full-size SUV class — some of it justified, some not. The situation is better than it used to be and, with the vast majority of buyers in Western Europe opting for diesel power, even at this level economy is at the forefront of buyers’ minds.

Audi believes that it is on the right track with its revised Q7. The big SUV has been popular with many since it was first launched. It is also one of only a few in this sector that can boast of being just as capable off-road as it is on.

Not that many owners will appreciate this, or even be concerned. Many buy the Q7 for its spacious cabin, ability to seat up to seven, the overall levels of refinement and the appeal associated with those four rings on the grille.

Now that grille has been subtly redesigned, along with the car’s front and rear lights and bumpers. The Q7’s tailgate has also been under the knife, while there are some new exterior colour combinations to choose from.

The same is true inside the Q7, with the minor controls gaining a little more in the way of chrome trim, and there are a few new trim and colour combinations to ponder.

Audi’s new navigation system, already available in other new models, makes a welcome appearance on the options list, along with a host of comfort and safety equipment.

While appealing, the Q7’s new headlights cannot match the importance of its new engine line-up. With diesel the dominant force in this sector, let us concentrate on the 4.2-litre V8 and, more importantly, the 3.0-litre V6 units.

Audi boasts of welcome improvements for the 340 brake horsepower V8 — power and economy are up a fraction, while CO2 is down. Not bad for such a big engine. The V6 goes one better with Audi’s decision to offer two versions, a regular unit and the company’s Clean Diesel variant.

Both offer near-comparable performance (237bhp, 0-62mph in 8.5 seconds) which, in the real world, translates into plenty of power, a sizeable reserve of torque when pulling up a hill or towing a boat along the shore is required.

What makes the Clean Diesel different is its added focus on economy and emissions. The CO2 rating of 234g/km and 31.7mpg is five lower and 0.7 higher respectively than the normal 3.0 TDI unit.

Although small changes in the grand scheme of things, the backroom effort has been considerable. While all six and eight-cylinder Q7s now come with regenerative technology that captures energy when the car is coasting and braking, the Clean Diesel includes an additive injected into the exhaust system to further clean up emissions. Incidentally, all this trickery makes the Clean Diesel engine an EU6-rated motor, which easily puts its ahead of the official 2014 deadline for compliance.

The additive is focused on reducing Nitrogen Oxide (NOx) particulates, which are often ignored by European legislators, but harmful nevertheless — the Americans are the real drivers behind reducing NOx in diesel vehicles.

This process, combined with a special catalytic convertor, has allowed Audi’s engineers to reduce such emissions by an impressive 90 per cent.

And this Q7 drives like any other, which is how it should be. The big Audi has always been a competent performer, and the revised car is no different.

Smooth, sophisticated and refined at speed, plus easy to drive around town, the Q7 is an agile and brisk car. In real terms, the Clean Diesel element is something you do not notice when driving.

You will probably be more interested in playing with the clever new sat-nav system, or listening to the car’s quality audio unit.

And then there is the ability to accommodate seven people without feeling like the car is busting at the seams.

It is true you will pay a small premium for this new green technology — around £1,500 — over the price of a regular V6 diesel Q7.

That said, it is a small price to pay for what is not coming out of the tailpipe. It is not as if you have to compromise on the driving or ownership experience, which has always been the Q7’s strong suit.

Model: Audi Q7 3.0 TDI Clean Diesel SE Peformance: 0-62mph 8.5 seconds, top speed 134mph Economy: 31.7mpg (combined) CO2 emissions: 234g/km Price: £42,640 Web: www.audi.co.uk