| 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 n (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 n (ii) a metal detergent other than (i); n 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. |