| abstract |
PROBLEM TO BE SOLVED: To provide a lubricating oil composition having low oil consumption, excellent in high-temperature oxidation stability and power transmission performance, and particularly suitable for use as a four-cycle engine oil for motorcycles. SOLUTION: A mineral oil base oil having a lubricating viscosity contains (a) a boron-containing succinimide-based dispersant in an amount of 0.01 to 0.08% by weight in terms of a boron content, and (b) a calcium-containing detergent containing calcium. 0.05 to 0.3% by weight in terms of content, 0.04 to 0.12% by weight of (c) zinc dialkyldithiophosphate in terms of phosphorus content, and 0.01% of (d) antioxidant. In an engine oil composition dissolved or dispersed in an amount of from about 5.0% by weight to 1% of the mineral base oil. A lubricating oil composition having a kinematic viscosity at 00 ° C. of 3 to 9 mm 2 / s and an evaporation loss of 14% by weight or less. |