1999 Honda Civic Owner's Manual - Page 251

Oxygenated Fuels Some conventional gasolines are being blended with alcohol or an ether compound. These gasolines are collectively referred to as oxygenated fuels. To meet clean air standards, some areas of the United States and Canada use oxygenated fuels to help reduce emissions. If you use an oxygenated fuel, be sure it is unleaded and meets the minimum octane rating requirement. Before using an oxygenated fuel, try to confirm the fuel's contents. Some states/provinces require this information to be posted on the pump. The following are the U.S. EPA and Canada CGSB approved percentages of oxygenates: ETHANOL (ethyl or grain alcohol) You may use gasoline containing up to 10 percent ethanol by volume. Gasoline containing ethanol may be marketed under the name "Gasohol." MTBE (Methyl Tertiary Butyl Ether) You may use gasoline containing up to 15 percent MTBE by volume. METHANOL (methyl or wood alcohol) You may use gasoline containing up to 5 percent methanol by volume as long as it also contains cosolvents and corrosion inhibitors to protect the fuel system. Gasoline containing more than 5 percent methanol by volume may cause starting and/or performance problems. It may also damage metal, rubber and plastic parts of your fuel system. If you notice any undesirable operating symptoms, try another service station or switch to another brand of gasoline. Fuel system damage or performance problems resulting from the use of an oxygenated fuel containing more than the percentages of oxygenates given above are not covered under warranty. Technical Information