Patent ID: 8609599

Claim:
A trunk piston marine engine lubricating oil composition 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, and, in a minor amount: (A) one or more oil-soluble phenolic compounds, comprising one or more of 3-pentadecylphenol and 5-pentadecylresorcinol, wherein 50 or more mass % of said one or more oil soluble phenolic compounds is 3-pentadecylphenol, where the pentadecyl group is linear and is attached to the aromatic ring at its first carbon atom, provided that, in the absence of an hydroxybenzoate detergent, the mass percentage of the phenolic compound is 4 or more.