| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lubricating oil composition improving the cleanliness of pistons and having≤1.0 mass% sulfated ash content. SOLUTION: This lubricating oil composition is obtained by comprising, or is made by admixing a major amount of lubricating viscosity oil, and minor amounts of (A) a dispersant additive composition and (B) a detergent additive composition, wherein the oil composition gives a sulfated ash content of at most 1.0 mass%, for instance, 0.3-0.9 mass%, preferably 0.5-0.7 mass%; has a total base number (TBN) of 4-9.5, for instance, 5-9, preferably 6-8.5; has at least 0.08 mass%, for instance, 0.085-0.115 mass%, preferably, 0.09-0.10 mass% of nitrogen derived from the dispersant additive composition, based on the mass of the oil composition; and has at least 25 mmol, concretely, at least 28 mmol, for instance,≤35 mmol of soap derived from the detergent additive composition per 1000 g of the oil composition. COPYRIGHT: (C)2005,JPO&NCIPI |
