Porsche will unveil its hybrid Cayenne before 2010. Developed with Volkswagen, it is expected to reduce fuel consumption by 30 per cent, allowing it to cover 100km on nine litres of petrol.

Hybrid versions of the VW Touareg and Audi Q7 SUVs are also expected. And the first products to emerge from the hybrid joint venture between General Motors, DaimlerChrysler and BMW could also appear before the end of the decade.

The European hybrids are said to excel in highway driving as well as in town. The Japanese hybrids tend to save the most fuel in city driving.