Is ethanol in petrol bad for your car or not? NRMA environmental expert Jack Haley outlines the issues.
The subject of ethanol in fuel has generated much discussion and some confusion. Ethanol is an alcohol, the same as in alcoholic drinks, and is often produced by fermenting plant juice containing high levels of sugar. Most ethanol in Australia is produced using wheat as a base.
NRMA is not opposed to bio-fuels, such as ethanol, and has promoted further research into bio-diesel. However, the situation with ethanol is very complex.
Ethanol is significantly different from petrol. While levels of up to 10 per cent ethanol in petrol appear to cause little or no impact on new vehicles, NRMA research in the early 1980s and a literature review by the Federal Government show specific impacts and potential problems where ethanol levels in petrol are over 10 per cent.
The government report notes problems or potential impacts with 20 per cent ethanol in petrol blends. Potential problems include engine knock, fuel system gum deposits being stripped away causing fuel filter blockages and plugging fuel metering components, perishing and swelling of the elastomeric and plastic materials in the fuel system on older vehicles, increased evaporative emissions from vehicles' fuel systems and increased aldehyde emissions from tailpipes.
Australian vehicle manufacturers have indicated they may not continue warranty coverage where petrol with over 10 per cent ethanol is used.
Ethanol contains less energy than petrol, so fuel consumption increases when ethanol is blended into petrol. At the 10 per cent blending level, fuel consumption increases by about 3.5 per cent, so motorists have to buy 3.5 per cent more fuel to travel the same distance.
If planting, growing, harvesting and production processes for ethanol have a minimum input of fossil fuels and fertilisers, there are Greenhouse advantages. Plants take carbon out of the atmosphere as they grow, which is returned to the atmosphere when fuel produced from the plant is burned. Therefore, ethanol production is theoretically 'Greenhouse-neutral'.
However, the Greenhouse benefit is reduced where diesel-driven agricultural machinery is used to produce the crop, where fertilisers are applied and fossil fuels are used for heating to encourage fermentation, all of which produce emissions.
NRMA seeks a cap of 10 per cent on the ethanol content in petrol, and clear labelling on bowsers dispensing ethanol blends. NRMA is also examining the issue of a mandated level of ethanol in petrol.
If research by the Federal Government (due at the end of 2004), on the impact on vehicles of blends over 10 per cent shows there is no risk to motorists, NRMA will review its position.
Responsibility for the collection of excise on fuels now lies with the Australian Taxation Office. If you suspect you have purchased adulterated fuel, report it to the ATO, rather than to the Customs Department.
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