Honda Harmony HS520A Owner's Manual page 46

TECHNICAL & CONSUMER INFORMATION
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 EPA-approved percentages of oxygenates:
ETHANOL —— (ethyl or grain alcohol) 10% by volume
MTBE ———— (Methyl Tertiary Butyl Ether) 15% by volume
METHANOL —- (methyl or wood alcohol) 5% by volume
Fuel system damage or performance problems resulting from the use
of an oxygenated fuel containing more than the percentages of
oxygenates mentioned above are not covered under warranty.
44
You may use gasoline containing up to 10% ethanol
by volume. Gasoline containing ethanol may be
marketed under the name "Gasohol".
You may use gasoline containing up to 15% MTBE by
volume.
You may use gasoline containing up to 5% methanol
by volume, as long as it also contains cosolvents and
corrosion inhibitors to protect the fuel system.
Gasoline containing more than 5% methanol by
volume may cause starting and/or performance
problems. It may also damage metal, rubber, and
plastic parts of your fuel system.