The number of vehicles being converted to LPG was up 36% on 2007’s figures, with 17,000 conversions carried out by approved installers in 2008 - the highest number of conversions in five years.

Calor's Autogas development executive Chris Taylor says the increase is due to a range of factors, including cost savings to run an LPG vehicle, reduced payback periods and the desire to be more environmentally aware.

“Motorists running LPG vehicles can expect to save up to 40% on fuel costs and in many cases can recover the cost of a conversion in under two years,” explained Taylor.

The total number of LPG vehicles on the roads now stands at around 155,000.