PORT VILA, Vanuatu — Tony Deamer stepped on the gas pedal of his vehicle but didn't change down a gear as it rounded a corner and sped up a steep hill.

Modified to run on coconut oil instead of diesel fuel, the four-wheel-drive took the slope without slowing down.

"Coconut oil is a bit more torquey, because it burns slower," said Mr. Deamer, 52, an Australian-born motor mechanic. "Normally, I'd have to shift down into first here, but with coconut oil, I can keep it in second gear."

Mr. Deamer lists other advantages coconut oil has over petroleum as a fuel: it doesn't make black smoke, it is less costly (at least in the South Pacific), it has the potential to stimulate employment among local coconut growers, and, perhaps most importantly for the world at large, it is an environmentally friendly fuel.

In what could prove to be a boon for both the environment and cash-strapped South Pacific islands, Mr. Deamer has succeeded in proving that automotive diesel engines, with very little modification, can run safely on coconut oil.

The discovery has huge potential for island nations like Vanuatu where the cost of imported oil is a heavy burden on the economy.

Helping the population is a main goal of Mr. Deamer's project, which he sees as an extension of his commitment to the promotion of social and economic development -- a commitment that stems from his practice of the Baha'i Faith.

"This is not a commercial venture," said Mr. Deamer, explaining that the entire project stems instead from his desire to help his fellow citizens -- and the world at large.

Late last year, some 200 mini-buses here were using a coconut oil/diesel mix on a daily basis, proving the concept. Mr. Deamer himself operates about a dozen vehicles on a pure coconut oil fuel.

"He's been talking about this for a few years," said Marc Neil-Jones, publisher and managing director of Vanuatu Trading Post and Pacific Weekly Review. "But people's interest has shot up since he started running a few cars on it.

"The copra industry is having major problems at the moment and the government is shoring up the price and it is costing a fortune," Mr. Neil-Jones said.

"So the possibility of using coconut oil as a fuel has the potential to really help the rural people."

Mr. Deamer says that if coconut oil fuel is widely accepted, it will increase the local demand for copra -- the dried coconut meat that is a major, although low-priced, commodity on world markets.

Such an increase in demand would provide jobs and money for rural villagers in Vanuatu, where cutting copra has been the major source of outside income. This, he says, will help to stem the tide of villagers who have fled idle copra plantations to urban areas.

"For every ton of diesel fuel that we can offset, we can put back some $200 into the local economy. And at those prices, people could earn a very good living cutting copra," said Mr. Deamer.

"This is really a great idea -- because it goes all the way back to the farmers who plant and cut coconut," said Leo Moli, head of the energy unit within the Vanuatu Ministry of Lands and Natural Resources. "And, if it succeeds, there will be a reduction in the importation of fossil fuels, especially diesel fuel."

The key to the entire project was proving that ordinary automotive diesel engines can run reliably on coconut oil.

"Tony has done groundbreaking work to show that coconut oil will work in automotive diesels without any major modification," said Rodney Newell, president of Renereltech, a small Vanuatu-based company that focuses on helping local businesses develop renewable energy.

"Vegetable oils are being used in other parts of the world in diesel engines," said Mr. Newell. "But this is a unique project in that neat coconut oil is being used. This is a first for the Pacific area."

Using coconut oil for fuel has several inherent problems. First, it tends to be thicker -- more viscous -- than other fuels. The unprocessed oil also usually contains more water and impurities than other alternatives.

Mr. Deamer has experimented extensively and solved many of these problems. He has developed a small and inexpensive pre-heater that lowers the viscosity of the oil before it enters the engine. And he has also worked with another local fuel distributor to develop filtration techniques to remove water and impurities.

Unlike many entrepreneurs, Mr. Deamer has been willing to share his findings widely, giving information to all concerned, even potential competitors.

Trained as a mechanic, Mr. Deamer came to Vanuatu from Australia in 1971. As a Baha'i, he sought to promote social and economic development, residing first on the outer island of Tanna, working as a mechanic for the public works department there.

In 1981, he relocated to Port Vila, first working for the Ministry of Education and then establishing his own automobile rental and repair business.

That enterprise has provided a good living for Mr. Deamer -- and a platform on which to experiment with alternative fuels. He has converted many of his rental cars to run on coconut oil, tinkering with the pre-heaters until they ran smoothly.

Baha'i principles guide his activities. In his business, he has hired and trained a number of female motor mechanics, a move that stems from his belief in the Baha'i ideal of equality between women and men.

"Work in the service of humanity is service to God," said Mr. Deamer. "That is the driving force of what I am trying to do, to leave behind something of value to Vanuatu, instead of just to Tony Deamer."

Mr. Deamer soon switched back to a discussion of the advantages of coconut oil fuel.

"One of the reasons I like using coconut oil instead of diesel fuel is you are putting back into the atmosphere the same carbon dioxide that the tree took out a year ago," said Mr. Deamer. "It's completely sustainable. Coconut trees are very efficient carbon absorbers.

"And coconut oil is also non-toxic," Mr. Deamer said. "What other Pacific fuel can you cook your fish and chips in and run your truck on?"