Breakthrough made in Diesel-LPG Conversion

For the first time diesel pickups can now be altered to run on liquid petroleum gas. A garage in Chiang Mai pioneered the technique.

Chiang Mai Yanyont Service can amend a vehicle's engine to run on gas. In the past, the engines had to be swapped for petrol-powered plants.

Ninety per cent of pickups sold are diesel driven. Only Toyota produces pickups and SUVs with petrol engines.

The garage's managing director Kiaittisak Singkhra says petrol engines need to be modified to make them work at lower stresses - at 110psi - instead of the factory specified 250psi.

Some engine parts need to be altered, including spark plugs and distributors, to accommodate lower stresses. He says LPG powered diesel engines experience no mechanical or technical problems.

However, it's not cheap. Compared with Bt18,000 to Bt20,000 to install LPG systems in a petrol-engine vehicle, diesel modification costs Bt55,000 for older models and Bt85,000 for newer ones.

Kiaittisak says his garage handles about five vehicles a day. There are 150 on the waiting list.

It's been installing LPG systems in petrol engines for 20 years and started with diesels last year.

More than 100 diesel conversions have been completed and no problems have been reported beyond the need for a little fine tuning.

Anuchit Klabprasit of the Don Muang Technical College questions the conversions, though. He says engines will wear out faster than usual and replacement of diesel engines with petrol ones is a "waste".

He adds fuel consumption rates of converted diesels will be much higher than petrol conversions.

Nevertheless, he concedes it's a "good investment in times of high petrol prices".