IT is the most fuel efficient BMW 3 Series model ever - but the best thing about the 320d EfficientDynamics saloon is it feels exactly the same as the full-fat Beemer it is based on.

The Germans have gone the extra mile with a number of changes made to the standard car all aimed at reducing running costs and the impact on the environment.

The result is a BMW that won't be running out of diesel in a hurry as the car averages at close to 70mpg, while carbon dioxide emissions are just 109g/km.

This is one clever car featuring an engine stop-start system, brake energy regeneration and electric power steering range. There's also longer gearing, lowered suspension, aerodynamic alloy wheel designs, Michelin Energy Saver tyres, modified gearshift indicator settings and a new flywheel.

As with the standard 320d, the EfficientDynamics model has a 2.0-litre diesel engine - but with 161 rather than 175bhp. BMW's engineers have compensated for this by raising the maximum torque level.

Thus the model may be environmentally friendly but it is still as brilliant to drive as any other 3 Series. Thanks to the improved torque the drop in power is not an issue and this is highlighted by a nippy 0-62mph time of eight seconds and a top speed of 142mph.

I did fear that the lowered suspension would damage quality of the ride but it is unaffected while the steering and handling are as sharp as ever.

The longer gearing keeps engine revs low to cut fuel consumption and this works together with the new flywheel helping to smooth out the vibrations normally expected when a diesel engine is barely above tickover.

BMW reckons that most drivers will, on average, be using 500rpm less than a standard 320d driver and having driven the car I'd say that was a distinct possibility.

The changes make the Efficient Dynamics model much cleaner than the standard 320d - which averages 58.9mpg and emits 128g/km - so it is exempt from the recently introduced showroom tax while road duty for private motorists will be £20 a year once the car is more than 12 months old.

Business users benefit as well as the car falls into the lowest category for company car tax while the companies they work for can also offset 100 per cent of the price-tag in their capital allowances in the first year of ownership.

The model offers standard equipment that mirrors the 320d SE's, but with 16-inch rather than 17-inch alloy wheels. Kit includes dual-zone climate control, reversing sensors, multi-function leather steering wheel and extended lighting.

Apart from the new wheels and slightly lower stance it looks just like any other 3 Series - although the Efficient Dynamics badges on the bootlid and inside give the game away.

The car oozes class. Everything has a solidly constructed, built-to-last feel, while the cabin materials are top quality. Numerous trim combinations allow buyers to tailor the interior to their own tastes.

There's a good range of adjustment for both the driver's seat and steering wheel but I did find the manual seat adjustment mechanism a little awkward to use. There's plenty of legroom in both the front and back seats but taller passengers may brush their heads against the ceiling in the rear.

The boot offers more than enough room for a family shopping excursion to spend the money saved on fuel.