Daniel Blackburn said motorists wanted alternatives to fossil fuels

The scheme converting diesel-powered cars to vegetable oil was launched by the West Wales Eco Centre in December.

The Pembrokeshire company said there had been a "very keen" response to the project, but added that some grants were still available.

The initiative is backed by the Welsh Assembly Government.

The grant halves the �1,200 cost of converting a vehicle.

The scheme is supported by Veg Oil Motoring organisation, also based in Pembrokeshire.

Daniel Blackburn, of Veg Oil Motoring, said: "The response to the project has exceeded expectations and with so many drivers wanting to access the scheme it is likely that the subtle smell of fried food will become more common on the roads of west Wales.

Rebate

"The interest shows how keen many motorists are in using this alternative to fossil fuels.

"The reasons for this are numerous - drivers see the importance of reducing carbon dioxide emissions and the benefits of using a fuel than can be grown in Pembrokeshire."

Mr Blackburn added that motorists could expect to cut their carbon dioxide emissions by about three tons a year.

The conversion can also help cut running costs, as fuel duty on cooking oil - at 27.1p per litre - is almost half the duty on petrol or diesel.

But in recent months, some companies producing the environmentally friendly fuel have been told by HM Revenue and Customs (HMRC) they are no longer eligible for the 20p-a-litre tax rebate.

'Carbon neutral'

In November, HMRC also demanded Plymouth Bio-Fuels in Devon pay �16,000 in back duty.

But Daniel Blackburn, from West Wales Eco Centre, said cutting costs was not the main advantage of the fuel.

He told the BBC News website: "When you fill up with used cooking oil, you're taking something that has been used for a purpose and you're driving a vehicle on that - so it's as near to carbon neutral as you could get."

An information evening about the scheme will be held on 25 January at the Cleddau Bridge Hotel in Pembroke Dock at 1900 GMT.