LIQUID petroleum gas will move ahead of the pack as the fleet industry increasingly focuses on which alternative fuel to use, rather than whether to use one at all. That is the message from Henry Clayton, European auto gas development manager for Shell LPG Europe, who says LPG offers a much more cost-effective option than its competitors in the 'green' fuel arena.

LPG and compressed natural gas recently tied as the most popular fuels to trial among fleets chosen to receive conversion subsidies from the Government-funded Energy Saving Trust's Powershift. Of the 318 successful fleets, 136 wanted to trial LPG and 135 CNG. Clayton believes that LPG will pull ahead of CNG as a realistic choice for urban fleets. This, he says, is largely down to simple maths.

He said: 'It costs around £1,500 to convert to LPG and double that for CNG. The tank size is another factor - a tank for CNG is typically two-and-a-half times bigger than its LPG counterpart. Fuelling is a major problem with CNG. It is more or less standard to fuel overnight with CNG, and faster fuelling tends to be very expensive. With LPG it takes around the same time as fuelling with petrol or diesel.'

Shell estimates fleets can already achieve savings after just 10,000 miles a year by switching to LPG from diesel and, with subsidies available for conversion costs, Clayton said LPG was a cost-effective option.