Abstract: A marine diesel cylinder lubricant composition having a total base number of at least 30. The composition includes at least 40 weight per cent of an oil of lubricating viscosity, at least one detergent prepared from at least two surfactants, preferably phenate and sulphonate surfactants, at least one boron-containing dispersant providing at least 100 ppm of boron, and at least one zinc-containing antiwear additive, preferably a zinc dihydrocarbyl dithiophosphate, providing at least 230 ppm, preferably at least 250 ppm, of zinc. The marine diesel cylinder lubricant composition exhibits reduced wear even when used with high sulphur fuels.

Abstract: A marine diesel cylinder lubricant composition for a marine diesel engine running on fuel having a sulphur content of less than 1.5%, the composition having a total base number, as determined according to ASTM D2896, of more than 30 and less than 70, and comprising at least 40 wt % of an oil of lubricating viscosity, and at least one detergent prepared from at least two surfactants, one of which is a salicylate. The marine diesel cylinder lubricant composition demonstrates good ability to reduce deposit formation, especially on pistons. The marine diesel cylinder lubricant composition also demonstrates good lubrication at temperatures above 250° C.

Abstract: A lubricating oil composition suitable for a trunk piston marine diesel engine. The lubricating oil composition comprises an admixture of: (A) an oil of lubricating viscosity, in a major amount; and (B) an oil-soluble complex overbased metal detergent additive, in a minor amount. The composition is substantially dispersant-free or contains 1, or less than 1, preferably less than 0.5, mass % based on the mass of the compositions, of a dispersant. The composition has a TBN in the range of 3.5 to 100, preferably 8 to 100.

Abstract: A gas-fuelled engine lubricating oil composition having a TBN in the range of 2 to 20 and comprising: (A) oil of lubricating viscosity; (B) a salicylate detergent having a TBN of 95 or less; (C) a detergent having a TBN of greater than 250; (D) an ashless dispersant; and (E) an anti-wear additive.

Abstract: A lubricating oil composition suitable for a two-stroke cross-head marine diesel engine. The lubricating oil composition comprises a base oil and an oil-soluble overbased metal detergent additive in the form of a complex wherein the basic material of the detergent is stabilized by more than one surfactant.

Abstract: A marine engine lubricating oil composition for a slow or medium speed diesel engine comprises a major amount of an oil of lubricating viscosity that contains a minor amount of a fuel oil with a residual fuel content and, admixed therewith, a minor amount of at least one oil-soluble or oil-dispersible ashless organic compound having at least two adjacent, substitutable carbon atoms being either part of an aromatic moiety or being connected by a double bond, each carrying an O— or O— and N-containing functional group, both groups being derived from a carboxy group.

Abstract: A lubricant suitable for use in a trunk piston diesel engine characterised by a power output of 200 kW or greater. The trunk piston diesel engine may be for use in marine, power generation or rail traction applications. The lubricant comprises a basestock of lubricating viscosity, an overbased metal detergent, preferably having an ash content of at least 0.85% sulfated ash, and an ashless or metal-free auxiliary additive comprising at least one of: an oil-soluble sulfurized alkylphenol, a phosphorosulfurized or sulfurized hydrocarbon, a sulfide of an oil, a fat or a polyolefin, or an amine phosphate.

Abstract: A lubricating oil composition suitable for a two-stroke cross-head marine diesel engine. The lubricating oil composition comprises a base oil and an oil-soluble overbased metal detergent additive in the form of a complex wherein the basic material of the detergent is stabilized by more than one surfactant.

Abstract: A marine engine lubricating oil composition for a slow or medium speed diesel engine comprises a major amount of an oil of lubricating viscosity that contains a minor amount of a fuel oil with a residual fuel content and, admixed therewith, a minor amount of at least one oil-soluble or oil-dispersible ashless organic compound having at least two adjacent, substitutable carbon atoms being either part of an aromatic moiety or being connected by a double bond, each carrying an O- or O- and N-containing functional group, both groups being derived from a carboxy group.

Abstract: A lubricating oil composition suitable for a trunk piston marine diesel engine.

Abstract: A gas-fuelled engine lubricating oil composition having a TBN in the range of 2 to 20 and comprising:

Abstract: A marine diesel engine lubricant composition having a TBN of at least 10 and preferably a VI of at least 90, comprises a major amount of oil of lubricating viscosity, and admixed therewith, minor amounts of an ashless antiwear additive and a metal detergent in the form of (i) an overbased metal detergent having a TBN at least 300, preferably at least 330, more preferably at least 400, and comprising a surfactant system derived from at least two surfactants, and/or (ii) a metal detergent other than (i); provided that, if detergent (ii) is present, the composition does not contain a minor amount of an extreme pressure additive, being up to 5.0 mass % based on the total mass of the composition.

Abstract: A marine diesel engine lubricant composition having a TBN of at least 10 and preferably a VI of at least 90, comprises a major amount of oil of lubricating viscosity, and admixed therewith, minor amounts of an ashless antiwear additive and a metal detergent in the form of

Abstract: An improved polybutene-free lubricant composition for marine diesel engines, comprising a major amount of oil of lubricating viscosity and, provided by admixing therewith, minor amounts of a) at least one of a borated dispersant or oil-soluble or oil-dispersible boron compound; and b) one or more overbased metal compounds the or each compound having a TBN of at least 300, with the proviso that if an overbased metal salicylate is present then the TBN of said salicylate is at least 200; wherein the TBN of the composition is at least 10 and the viscosity index of the composition is at least 90.

Abstract: A dispersant additive package for cylinder lubricant for marine diesel engines comprising a borated dispersant and a high molecular weight polybutene provides a lubricant with improved viscosity, wear, oxidation and deposit performance.

Abstract: Marine diesel cylinder lubricant composition comprising a major amount of an oil of lubricating viscosity and a borated dispersant; one or more overbased metal compounds and a zinc dialkyl dithiophosphate wherein the boron content of the oil is from 0.01 to 0.016 wt %, the zinc content of the oil is from 0.02 to 0.023 wt % and the TBN is at least, 60 given surprising wear results particular in cylinder liner and piston ring wear.