| abstract |
The present invention is a system lubricating oil for crosshead diesel engines, which generates less deposits and has excellent high temperature cleanliness and coking resistance, even when using a base oil having a high saturated hydrocarbon content, and (i) a kinematic viscosity at 100 ° C is 8.2 to 12.6 mm2 / s. And a metal-based detergent (B) and zinc dithiophosphate (C) in a base oil (A) having a saturated hydrocarbon content of 90% by mass or more, and the metal-based detergent (B) is contained as a soap component-containing concentration per 100 g of the composition. A lubricating oil composition containing at least 2.5 mmol, a phosphorus content of 200 to 1000 mass ppm and a basic value of 7.5 mgKOH / g or more, and (ii) a metal-based detergent (B) and zinc dithiophosphate (C) in the base oil (A). ) And an amine antioxidant (E), the composition contains 0.3% by mass or more of the amine antioxidant (E) based on the total amount of the composition, a base value of 6.5 mgKOH / g or more, and a phosphorus content of 200 to It provides a lubricant composition of 1000 mass ppm. |