FLEETS face lean pickings if they are looking for the maximum Energy Savings Trust Powershift 75% grant for the extra cost of a 'green' car - with just Ford, Vauxhall and Volvo models represented. For vans, the range is nearly as small, with Ford, Mercedes, Skoda, Vauxhall and Volkswagen models - either in-house or aftermarket conversions - represented and only Iveco Ford offering an alternative fuel light truck.

However, Powershift manager Jonathan Murray, said there were 40 models awaiting funding and more were expected to appear on the register during the year. The list highlights the importance of choosing alternatively-fuelled vehicles carefully to ensure the highest grant is available to cut the extra costs involved in converting to cleaner fuels, as models in other bands only qualify for grants of 50% or 25% towards the extra purchase price of a vehicle.

All the top scoring bi-fuel cars run on liquefied petroleum gas, except the Volvo S and V70 bifuel which runs on compressed natural gas. Vauxhall's in-house conversions which receive the maximum grant are the Omega 2.0-litre 16-valve LPG, which cuts overall emissions by 89% compared to current European standards, and the Vectra 2.0-litre, which cuts emissions by 91%.