Patent ID: 9534185
Date: 2017-01-03
CPC Classifications: C10M,C10N

Claim:
1. A trunk piston marine engine lubricating oil composition having a TBN in the range of 20 to 60 mg KOH/g, for improving asphaltene handling in use thereof, in operation of the engine when fuelled by a heavy fuel oil, which composition comprises or is made by admixing an oil of lubricating viscosity, in a major amount, containing 50 mass % or more of a Group I basestock, and in respective minor amounts: (A) a calcium alkyl salicylate detergent system providing 40 to 90 mmol of calcium alkyl salicylate per kg of the composition, as determined by titration; and (B) 1 to 7 mass % active ingredient, based on the mass of the composition, of a polyalkenyl-substituted succinic acid or succinic anhydride, wherein the polyalkenyl group is derived from a polyalkene having a number average molecular weight of from 350 to 950.