Volkswagen's fourth-generation Polo takes to the road with the accent firmly on diesel power.

The resurgence in the popularity of diesel engines has led the German car-maker to predict that 45 per cent of its sales in the UK this year will be diesel. For some models -- the Sharan, Golf Estate and Passat Estate -- it expects more than three quarters of the models sold to use diesel power.

So the newly-minted Polo, which has a larger body, new running gear and suspension and improved specification, comes with a new range of engines -- three of them diesel, including the most powerful, a 100 horsepower unit.

Later in the year, three other petrol engines will join the range, including an 85 horsepower direct injection petrol, which is expected to deliver 15 per cent better fuel economy than current petrol models.

Five specification levels are available -- 16V and GTI have been removed, with the line-up now E, S, S A/C, SE and Sport. On the road, the range-topping 1.9-litre turbo-charged diesel engine -- which also appears in the Passat, Golf and Bora models -- is as punchy as you would expect, coupled with ride and refinement associated with a Golf-class car.

The 1.2-litre, 65 horsepower petrol engine is another star performer, delivering a surprising kick, while still offering the promise of almost 50 miles per gallon. The three-cylinder engine is remarkably refined, thanks largely to the use of balancer shaft technology which irons out much of the vibration often linked with three-cylinder units.

To give you some idea how the Polo has grown over the years, the new Polo is about seven inches longer than the original Golf model, though it's still smaller than the latest Golf. The front seats both now adjust for tilt and reach and for height (S models and above) with the 'pump action' handle found in the Golf. All models have a rake and reach adjustable steering wheel and seat belt height adjustment.

The tailgate now opens higher, allowing unobstructed easy boot loading, while the bootspace has also been increased. In addition, the luggage area is more useable with four load-lashing points.

Prices start from £7,995 on the road for the 1.2-litre 55 horsepower, exactly the same as the model it replaces.