Volkswagen Passat

	Pushing technology to the limit is what car manufacturers should be all about - and that's exactly what Volkswagen has done with the Bluemotion

Pushing technology to the limit is what car manufacturers should be all about - and that's exactly what Volkswagen has done with Bluemotion. It combines a variety of tweaks, and can be applied to any VW model to create the cleanest and most fuel-efficient car in the line-up.

We've already been impressed by the Polo Bluemotion and Passat saloon. So how does this practical estate version perform? It uses the same modified 105bhp 1.9-litre TDI engine as the four-door, and this car gets lengthened gear ratios.

Underneath, special spoilers have been added to improve airflow, and the ride height has been lowered.

Even though the load-lugger is not quite as slippery as the saloon, there are still some significant gains in fuel economy. It rises from 47.9mpg on the standard TDI to 54.3mpg, giving an epic range of 839 miles. Thanks to the tweaks, CO2 emissions drop by 19g/km to 137g/km, which means the estate falls from the 20 per cent company car tax band to 18 per cent.

Covering 0-62mph in 12.4 seconds it's not especially quick, but on the move the 250Nm of torque pulls well. And with those aerodynamic changes raising the maximum speed by 3mph to 118mph, it's a great motorway car.

Factor in the huge 1,731-litre boot space and standard-fit climate control - plus a neat light on the dash which tells you when is the most economical time to change up - and you've got a practical, well equipped car.

There is a downside, though: the price! VW estimates Bluemotion adds £1,000 to the cost of the Passat S - taking this car to a hefty £18,415.