Smelling just like coconut biscuits straight out of the oven, the exhaust is a big improvement on an old diesel engine belching acrid black smoke.
All over the Pacific power authorities, private companies and entrepreneurs have been experimenting with coconut oil as an alternative to diesel fuel for vehicles, power generators and even ships.
"The idea goes right the way back to Mr Rudolf Diesel. He invented the combustion engine to use peanut oil," says Jerry Kramer, chief executive of Pacific International Inc, a company pioneering the use of coconut oil in the Marshall Islands.
The use of coconut oil received a boost in the last couple of years as oil prices hit record heights and coconut oil fell to around 550 US dollars a ton (tonne) in the volatile world commodity markets.
Coconut trees are found everywhere in the Pacific's tropical islands. The dried white flesh, known as copra, from six to 10 coconuts produces a litre of oil, making the substitution for expensive diesel seem a no-brainer.
But ironically the growth in the use of biofuels worldwide has helped push the price of crop oils higher and coconut oil now fetches nearly 1,000 dollars a ton.
"There is strong demand for vegetable oils, there is a huge demand in the US and Europe," says Jan Cloin, the energy advisor at SOPAC, the Secretariat of the Pacific Islands Applied Geoscience Commission based in Suva.
"The Pacific island countries could get into a situation where they cannot afford to use the oil themselves and would profit more by sending their oil to other countries."
Kramer's company exports most of the oil from the Tolobar mill it operates for the Marshall Islands government and its coconut oil fuel projects have recently taken a back seat.
"At the peak we used 100 percent coconut oil in ships with 1,000 horsepower engines and all the way down to five horsepower generators," he said.
But he remains committed to the idea, especially using coconut oil to generate electricity in remote islands, where diesel is particularly expensive.
Coconut oil was used as a substitute for diesel in the Philippines during World War II when diesel was scarce but it is only in recent years the idea has taken off.
The rising cost of oil, worries that oil will run out and increasing concerns about the environmental impact of fossil fuels have all boosted attempts to find alternative energy sources.
In the Marshall Islands, Kramer has been experimenting for several years with trying pure coconut oil in some of his vehicles, as well as heavy machinery and even tug boats and a cargo ship.
Some modern diesel engines are less tolerant of pure coconut oil. Another problem is that coconut oil starts to solidify below 25 degrees Celsius (78 Fahrenheit) -- but that is not a problem on many tropical islands.
Kramer found carefully filtered coconut oil with excess moisture removed worked perfectly in many diesel engines.
"With some of our trucks we run, we've been running on coconut oil for years and we haven't had a problem after four or five years.
But for many engines, a blend with diesel worked best.
"We did blends anywhere from 10 percent to 90 percent (with diesel) and we found the most tolerance for all types of engines was a 50-50 blend."
Australian-born entrepreneur Tony Deamer has also been experimenting in Vanuatu, running some vehicles from his own hire car and car dealership on pure coconut oil.
He has also sold a blend of 80 percent coconut oil and 20 percent kerosene as a diesel alternative under the Island Fuel brand.
Island Fuel has been on hold recently due to some equipment problems but Deamer says it will be up and running again soon.
Experiments with power generators have also been successful. In Vanuatu, electricity company UNELCO has been using diesel blended with coconut oil to run a large four megawatt generator.
Deamer says they are gradually increasing the proportion of coconut oil, which is 15 percent now, to see how the generator performs.
On Savaii island in Samoa, the electricity company has been running one generator on a coconut oil blend with success.
Deamer says substituting coconut oil for diesel will boost the declining copra industry.
"My motivation is partly trying to keep some money going overseas here in the country instead, and keep some employment in rural areas," he said. "I think it still has a future, I think we can make it happen."
Cloin says the economics of using coconut oil for fuel are marginal, although the copra industry is already subsidised in many island countries, making diesel substitution more viable.