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.