More drivers than ever are converting their cars to run on liquefied petroleum gas (LPG) as petrol prices continue to rise.
The LPG Association says that the number of people using the fuel has increased from 3500 in 1998 to 150,000 this year.
The organisation also says that the number of drivers making the switch has doubled this year, with garages struggling to keep up with demand.
LPG sells for about 49p a litre, compared with 117.28p for a litre petrol.
Conversions cost about 2000 and involve installing an additional tank, extra fuel lines and injectors into vehicles. Some tanks allow a car to travel up to 300 miles before refuelling.