Frankfurt motor show 2007 - Volkswagen Bluemotion

Volkswagen is about to blitz the market with a range of clean diesel cars to be sold under the BlueMotion banner.

Six new models are on display at Frankfurt, joining the Polo, Passat and Passat Estate that were announced earlier this year.

The newcomers include every variant of the Golf – hatchback, estate, Golf Plus, Touran MPV and Jetta saloon.

The Polo BlueMotion is the first to arrive, going on sale in the UK later this year, with the others arriving progressively throughout 2008.

The Golf BlueMotion, due in the UK next January, could turn out to be a popular choice among London commuters.

With CO2 emissions of just 119g/km and a fuel economy figure of 62.8mpg, owners would be able to drive it into central London without having to pay the congestion charge if Mayor Ken Livingstone's new emissions-based charging structure is approved.

All BlueMotion models combine revised diesel engines with economy-minded gear ratios, aerodynamic modifications and low-rolling-resistance tyres.

The Golf family will use the 1.9-litre, 104bhp engine also fitted to BlueMotion Passats. Software changes reduce its idling speed, while a particulate filter traps specks of soot in the exhaust.

The new gear ratios lower the engine speed when running in third, fourth and fifth, helping to save fuel.

The suspension has been lowered to improve airflow under the car, and there is a new, smooth underbody.

Even the front grille has been almost enclosed to reduce air turbulence that would damage fuel economy. However, to ensure the engine gets enough cooling air, two fans are fitted.