1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 293Get this manual
DF40QHDF50QH 11-2 Data DF40QH DF50QH
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
SE, SF, SG, SH, SJ