Ethanol in Maine gasoline

October 31, 2008

Contact: Melissa Morrill (207) 287-6102
Lynne Cayting (207) 287-7599

(AUGUSTA)—It’s not by state mandate, but it’s here. By early next week, most gas stations will be selling fuel containing 10% ethanol, a domestic product made from fermenting certain agricultural crops and wood. A combination of federal regulatory requirements, tax incentives and market forces accounts for the fuel distributors’ business decision to supply the new blend, taking some drivers by surprise and prompting questions about performance and environmental impact.

Many of those questions have come to the Department of Environmental Protection (DEP) because of agency efforts to reduce air pollution through control of emissions from cars and trucks. Although the State does not require the sale of ethanol-blended gasoline, DEP has developed a web site ( to help address the most common inquiries.

Most often heard is “what is it?” Ethanol is what is known as a “renewable fuel”, meaning that it is made from crops and materials that are not in finite supply, like oil. In gasoline, it performs as an effective octane enhancer and also serves to reduce harmful emissions.

Another common question is about performance-- how use of the blended fuel can affect vehicles, motorized boats and other gasoline powered equipment. By far the vast majority of engines should not encounter any performance related problems; however, users of the fuel can expect about a 3% loss of fuel economy.

In addition, some engine/fuel system components in older (pre 1980) engines may not be compatible with ethanol. For instance, certain types of rubber used in seals and hoses may deteriorate more rapidly when exposed to ethanol blended gasoline.

For boat owners, ethanol, being a solvent, may scour fuel systems, overburden filters and breakdown certain fiberglass gas tanks. Anyone who has questions about their vehicles, boats, motorcycles, snowmobiles, ATVs, lawn and garden equipment should contact the engine manufacturer. For more information about ethanol blended gasoline, go to