MotorbikeWriter has frequently suggested riders steer clear of using ethanol fuel in their motorcycles and the U.S. Environmental Protection Agency agrees that it can damage motorcycle engines.
The US agency says ethanol-blended fuels increase exhaust temperatures which can cause component failure. It has proposed a cutback in its availability.
Ethanol is a type of alcohol produced by fermentation of sugarcane or grain. In Australia, ethanol content in unleaded fuel is limited to 10% (E10), the US it’s 15% but some countries use 85% or even higher.
E10 is becoming more prevalent throughout Australian service stations and NSW service stations even have to stock a minimum requirement of the fuel which means that there is no alternative at some NSW servos.
According to the Federal Chamber of Automotive Industries, only post-1986 bikes and ATVs made by BMW, Harley, Polaris and Victory can safely use E10. No Japanese bikes and no Piaggio products can use it. The FCAI doesn’t mention other brands, but it can be assumed ethanol blends are not suitable.
Ethanol doesn’t work with carburettors or mechanical fuel injection. It is also a solvent which attacks metallic and rubber-based fuel lines, and has an affinity to water that can cause steel fuel tanks to rust.
For some time the American Motorcyclist Association has been fighting the distribution of E15 fuel blends in an effort to protect motorcycle and all-terrain vehicles from the damage that ethanol causes. It has applauded the EPA’s decision to roll back the requirement for wider distribution and use of E15 under its Renewable Fuel Standard.
According to the EPA, ethanol makes engines run leaner (with a higher air to fuel ratio) which can lead to increased exhaust gas temperatures. It ays that could gradually destroy emission control hardware and performance, possibly causing catalyst failure. Ethanol can also cause “materials compatibility issues”, which may lead to other component failures.
Riders should also be aware that the higher octane rating on some ethanol fuels may be misleading. For more information, read this.