It is expected to show that liquefied petroleum gas and compressed natural gas should be the choice fuel for 'green' fleets. But the Inland Revenue said this pollution rating system will not form the basis of any benefit-in-kind system and will therefore act simply as an influence on buying choices. For more than a year Don Ridley, Environment Agency environmental planning manager, has been developing the scheme which considers the impact on global warming and air quality of a car's use and also the effect on the environment of the supply and use of its fuel.
Emissions like CO2 and oxides of nitrogen and sulphur are taken into account before a vehicle is given an environmental rating. Ridley said: 'CNG and LPG are both cleaner and cheaper than traditional alternatives - whereas diesel is the dirtiest of all fuels. The fleet manager using diesel because it's so much more cost effective than petrol, but who is worried about its environmental impact, can choose the gas option which is both economical and clean. The information could lead to a change of buying patterns.'
Ridley's vehicle ratings are set to be published on the agency's website in June. But an Inland Revenue spokeswoman said: 'There are no plans to concentrate on anything but CO2 in our 2002 tax system. The new system can be used as a buying guide for drivers looking for 'green' cars.'