marine engine lube composition, methods of preparing a marine engine lube composition, and operating a marine engine, and use of a combination of additives

摘要

marine engine lube composition, method for preparing a marine engine lube composition, use of a combination of additives, and, method for operating a marine engine a tbn 20 to 60 stem piston lube composition, comprising (a) a high saturation low sulfur lubricating viscosity oil in a principal amount; (b) a superbased metal hydroxybenzoate detergent additive; (c) a polysobutene succinic anhydride additive (1-7 mass%); and (d) a meta-linear pentadecyl phenol additive (10.1 to 10 mass%), the weight ratio of (d) to (c) being less than 1 and the combined treatment rate of (b) , (c) and (d) being from 5 to 30%. The composition is useful for improving asphaltene dispersion when lubricating a medium-speed compression-ignited marine engine powered by a heavy fuel oil.