Patent ID: 9353330
Filing Date: 2016-05-31
CPC Classification: C10M,C10N

Claim Text:
1. A trunk piston marine engine lubricating oil composition having a TBN 20 to 60 mg KOH/g, for a medium-speed four-stroke compression-ignited marine engine, comprising or made by admixing: (A) an oil of lubricating viscosity in a major amount containing greater than or equal to 90% saturates and less than or equal to 0.03% sulphur; (B) a detergent additive, in a minor amount, comprising one or more overbased metal hydrocarbyl-substituted hydroxybenzoates; (C) an additive, in an amount of 1 to 3 mass %, comprising one or more polyisobutene succinic anhydrides derived from polyisobutene having a number average molecular weight of 350 to 1000; and (D) an additive, in an amount of 0.1 to 2 mass %, comprising one or more sterically unhindered meta linear pentadecyl phenols, wherein the weight ratio of (D) to (C) is 0.2 to 0.55, and the combined treat rate of said hydroxybenzoate(s), anhydride(s) and phenol(s) is in the range of 5 to 19 mass %.