Every mandatory E10 state has exemptions to their blending law, because there are a number of piston engine applications that should not, and some that cannot, use ethanol blended gasoline. Unfortunately the exemptions are not uniform. They vary from only one exemption in Washington, aircraft, to a universal exemption of premium unleaded in Missouri. All states exempt aircraft usage, but most states like Oregon and Washington make it almost impossible to get unblended gasoline. Oregon is the only state that allows for unblended regular and premium gasoline for the exemptions, and then makes it almost impossible to get any unblended gasoline. All other mandatory ethanol states just allow clear premium unleaded gasoline for the exempted classes.
The following piston engine applications should not use ethanol blended gasoline:
- Any 2 cycle engine used in tools, watercraft, snowmobiles, etc., or small 4 cycle engines.
- Any engines used in an emergency stationary engine application like a generator, especially in a humid climate.
- All watercraft. Ethanol blended gasoline should never be used in a marine environment.
- Antique and classic cars and classic motorcycles.
- All aircraft.
All of these users must be able to get ethanol free (E0) gasoline. If you live in a state without a mandatory ethanol blending law, you have no exemptions, ethanol will eventually be blended into all of your unleaded gasoline and there is no requirement in EISA 2007 to label gas pumps with ethanol content.