Ethanol, octane and corrosion

Ethanol and Octane

In spark ignition engines, ethanol can run at a much higher exhaust gas recirculation rate and with higher compression ratios. Ethanol has a higher octane rating than most petroleum – usually at 113 RON (Research Octane Number) – and creates very few particulates. Octane is the measure of a fuel’s ability to resist “knocking”, which a driver may detect as a “pinging” noise coming from the engine. Knocking is basically the burning of the fuel in the engine’s combustion chamber. The higher the fuel’s octane number, the better the fuel and the more resistant it will be to knocking.

Ethanol and Corrosion

In the past, ethanol has been attacked for being corrosive and for damaging fuel system components. However, all types of petroleum products have corrosive properties and oil companies are required by law to add corrosion inhibitors not only to ethanol-blended fuels but also to other petroleum products. Corrosion inhibitors are fuel additives that inhibit or suppress the corrosive properties of fuel, thereby preventing the corrosion or rusting of the fuel tank as well as the other components of the fuel system.

Provided your ethanol blended fuel is purchased from a reputable source, there is no potential for erosion. This is because the ethanol sold in Australia must – by law – contain a corrosion inhibitor additive to overcome previous issues of improper use of lower quality ethanol or at inappropriate blends without the corrosion inhibitor.

In short – ethanol is safe for use in your car!