When the United States sneezes, the world catches cold.” Fair or not, that old adage has gained a lot of traction lately. But many in Australia’s boating industry are discovering that, when discussing the topic of ethanol fuel, that cliché may be all-too appropriate.

As the American Environmental Protection Agency considers increasing the amount of ethanol in fuel in the US, boat mechanics across America are experiencing a boom in carburettor and fuel system rebuilds. And complaints about ethanol are now a common feature on internet boatie discussion boards in the US.

Predictably, this has led to a bevy of lawsuits and counter-lawsuits, effectively putting ethanol on trial. Last June, a California law firm filed a class-action lawsuit alleging oil companies failed to inform boat owners of the damaging effects of ethanol on fibreglass fuel tanks. Other lawsuits, some plainly frivolous, have followed.

But even as many of the lawsuits have been more about the pursuit of money than the pursuit of justice, many of the facts raised in the cases are compelling. What’s indisputable is that the use of ethanol carries potential risks for many boat engines and fuel systems. And as Australia ramps up its own use of ethanol, many marine industry insiders are suggesting that boaties here are in danger of experiencing some of the consequences currently being experienced in the US.


Long touted as a miracle fuel that can help save the world from global warming, ethanol in Australia is produced from grains or sugarcane grown in Queensland and NSW. Because it’s an oxygenate, ethanol burns cleaner than standard petrol and reduces carbon monoxide emissions and green house gases.

Legislation in Australia imposes a 10 per cent cap on the concentration of fuel ethanol blends, so the ethanol available at bowsers in Australia, known as ‘E10’, is actually a blend of 90 per cent unleaded petrol and 10 per cent ethanol.

E10 is available throughout Australia. Understandably, it’s more widely available closer to the sources of production in Queensland and NSW. According to the Queensland Government website, by 2010 it will be compulsory in Queensland for five per cent of the total regular unleaded fuel available to contain ethanol.

Not to be outdone, the Federal Government has set a goal for the sale of 350 million litres of E10 fuel each year by 2010. To reach that goal, the Government has given ethanol fuel producers capital grants and has exempted all Australian-produced ethanol from fuel excise tax until July 2011.

For cars and trucks, the implementation of ethanol blends in Australia has gone relatively smoothly. Over the years, car manufacturers have developed plastics and rubbers that are durable enough to withstand the corrosive effects of ethanol on tanks, hoses, seals and anything else the fuel touches.

However, boat manufacturers have not been so forward in their thinking. Despite obvious indicators that the use of ethanol in Australia was on the rise, many boat builders were slow to adapt. The result, many say, is that a lot of the boats on the water today are susceptible to all sorts of malfunctions attributable to the use of ethanol, from clogged fuel lines to disintegrating fuel tanks.


Gary Fooks is the chairman of the Eco-Friendly Fishing Association and a consultant to the boating industry and government on a wide range of subjects. For years, Fooks has spear-headed a one-man campaign to warn boaties and boat manufacturers about the dangers of ethanol use.

After tracking the history of ethanol’s impact on boaties in the US, Fooks is absolutely convinced about ethanol’s potential for harm. “Even one tank of E10 could mean an expensive trip to the workshop,” he says. “Boats and ethanol simply don’t mix.”

According to Fooks, the risk for boat owners comes from three crucial characteristics of ethanol: it’s a powerful solvent, it doesn’t stay mixed with petrol and it has a very short shelf life.

Fooks concedes that for most new boats, the use of E10 fuels won’t be a problem. But he strongly believes that if your boat is more than a few years old, or has a fibreglass fuel tank, you have reason to be concerned. “Up to 80 per cent of boats on the water today in Australia are susceptible to problems due to ethanol use,” he says, “And up to 10 per cent of those boats are at risk of major damage.”

Although Fooks’ estimates aren’t accepted by everyone in the marine industry, few dispute that boat owners need to be cautious about their use of ethanol. Recently, the Queensland Government, NSW Maritime and even ethanol producers like BP, Shell and Caltex have issued statements warning boat owners about the harmful effects of ethanol.

Because ethanol is a strong solvent, it can eat into fibreglass fuel tanks, drawing out resins, which are carried into the engine where they clog filters and carburettors or injection systems. It can also dissolve many of the rubber materials found in fuel systems.

Ethanol is also ‘hygroscopic’, which means it absorbs moisture from the air, which can lead to storage problems. If ethanol becomes saturated with water – which can happen when it sits for long periods of time, it undergoes something called “phase separation”. During phase separation, ethanol separates from the petrol, forming two separate layers. After phase separation, straight petrol floats at the top of the tank and the sludge of ethanol and water sinks to the bottom, from where the engine’s fuel is drawn. After phase separation occurs, the fuels can’t be remixed; the boat owner has no choice but to completely empty the tank. Engines designed for petrol will not run properly, if at all, on straight ethanol.


If you are planning to use ethanol, you’ll need to adapt to avoid the pitfalls that can be associated with its use. Coming into the winter months, the most obvious potential problem is phase separation in storage (pictured right). To avoid this, you have two options:

Fill the tank with straight ULP or premium unleaded petrol (without ethanol), while adding a fuel conditioner to your fuel. Then run the engine to get the treated fuel throughout the system before you put the boat into storage.

Remember that phase separation can’t be avoided when storing E10 over a long period of time. If you have E10 in your fuel tank, completely drain your fuel system before you put your boat away for the winter.


Despite the fact that there has been plenty of anecdotal evidence of marine engine problems related to ethanol use in America, so far, similar evidence in Australia has been hard to find.

Granted, ethanol use in Australia has not been as widespread here as it has been in the US. However, unleaded petrol with 10 per cent ethanol has been used in one form or another in Australia for almost 20 years, so it is something of a mystery that almost all of the Australian mechanics, marina owners and marine experts contacted for this article had yet to see any actual ethanol-related damage.

While noting that he doesn’t use ethanol fuel in his own boat, Phil Johnson, Club Marine’s National Claims Manager, wondered if perhaps the claims against ethanol have been exaggerated.

“I think it’s a bit of a furphy,” Johnson said. “I haven’t seen much evidence of an increase in claims by Club Marine members over ethanol damage.”

The team at the Club Marine Recovery Centre in Braeside, Melbourne agreed with Johnson. The Recovery Centre’s Darryl Humphreys, who sees a lot of damaged boats during an average week, said he hadn’t seen a single example of ethanol damage to boats.

Ethanol is not widely available in Victoria, but even in Queensland, which is the lead state for ethanol use, Club Marine State Manager, Chris Grice also had trouble finding a direct link between ethanol use and mechanical damage.

“I know of ethanol’s unsavoury reputation,” Grice said. “But we just have not seen mechanical damage in our claims traced directly to its use.”

So, how is it that Australians have so far been spared? Paul Dawson, National Training Manager for BRP Australia, importers of Evinrude outboards and Sea-Doo PWCs, offered a highly technical, but completely reasonable explanation: MTBE. Prior to the widespread use of ethanol in the US, many Americans used a fuel additive called MTBE (methyl tertiary butyl ether). After it was found to be a dangerous pollutant, production of MTBE in the US ceased. In Australia, the use of MTBE in fuel has always been limited. Dawson suggests that many of the problems that US boaties have reported may have something to do with corrosion caused by MTBE, not ethanol.

A second explanation was offered by Chris Grice: the bush telegraph. In this scenario, Aussie boaties have benefited from the hard lessons learned by boaties in the US and have avoided ethanol-related damage because of a grass-roots, word-of-mouth campaign to warn one another of the potential dangers of ethanol.

Regardless of the reasons, the potential for risk remains. And as ethanol fuel blends become more and more common, Australian boaties will need to ensure that they take steps to avoid the detrimental effects of improper use of the fuel. Although the Queensland Government has been quick to point out that “the use of E10 in marine outboards is not mandatory”, the use of caution when considering E10 fuel for your boat certainly is.


Most manufacturers of late-model marine engines approve the use of E10 in their products.

BRP-Evinrude: Evinrude motors can tolerate up to 10 per cent alcohol in fuels, (which is the maximum currently sold in Australia)

Honda: Honda engines are designed for good performance and efficient operation using petrol containing from 0 to 10 per cent ethanol

Mercury: Mercury engines will withstand up to 10 per cent ethanol in gasoline

Suzuki: Suzuki recommends the use of pure petrol, but can operate efficiently with 10 per cent ethanol

Yamaha: All 2008 and later models are suitable for use with ethanol E10 blended fuel. Models prior to 2008 are not suitable for ethanol blended fuel.

Club Marine recommends checking with the manufacturer of your engine to see if any additional precautions are required for E10 use for your specific boat model