2006-2009 Suzuki LT-Z50 QuadSport ATV Factory Service Manual, Page 9Get this manual
GENERAL INFORMATION
FUEL AND OIL RECOMMENDATION
FUEL (FOR USA AND CANADA)
Use only unleaded gasoline of at least 87 pump octane (R2M2) or 91 octane or higher rated by the Research MethodGasoline containing MTBE (Methyl Tertiary Butyl Ether), less than 10 ethanol, or less than methanol with appropriate cosolvents and corrosion inhibitor is permissible