1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 12Get this manual
1-7 GENERAL INFORMATION Data DF40T DF50T
FUELOIL
Suzuki highly recommends that you use alcohol-free unleaded gasolinewith minimum pump octane rating of 87method) or 91 (Research method)However, blends of unleaded gasoline and alcohol with equivalent octane content may be used
Engine oil
API classification Viscosity rating
SE, SF, SG, SH, SJ SAE 10W-40
Engine oil amounts
L (USImpqt)