Patent ID: 9012382
Filing Date: 2015-04-21
Classification: C10M,C10N

Abstract:
1. An internal-combustion engine crankcase lubricating oil composition having a sulphur content, expressed as atoms of sulphur, of not greater than 0.3 mass %; and a sulphated ash content of 0.5 to 0.8 mass %, which composition contains, or is made by admixing, the following additive components: A. 2 to 6 mass % of at least one oil-soluble or oil-dispersible nitrogen-containing derivative of a polyisobutenyl-substituted mono- or dicarboxylic acid, anhydride or ester, the polyisobutenyl-substituted mono- or dicarboxylic acid or ester being made from polyisobutenyl having a number average molecular weight of from 1500 to 3000 exclusively by the thermal “ene” reaction, being the sole ashless, nitrogen-containing dispersant in the lubricating oil composition and providing from 0.03 to 0.07 mass % of nitrogen in the lubricating oil composition; B. 0.5 to 3 mass % of at least one oil-soluble or oil-dispersible overbased calcium sulfonate, being the sole overbased metal detergent system in the lubricating oil composition, C. no greater than 1.3 mass % of a phosphorus-containing antiwear agent providing from 0.05 to 0.08 mass % of phosphorus into the lubricating oil composition, and; D. 0.01 to 10 mass % of at least one olefin copolymer viscosity modifier.