| abstract |
This invention concerns the lubrication of crosshead diesel engines, for example marine slow speed crosshead diesel engines. Lubrication is effected with a lubricant composition comprising a major amount of base oil and minor amounts of an anti-wear additive and of an extreme pressure additive. Good lubrication is achieved between metal surfaces at elevated temperatures and high contact pressures. Preferred compositions of the invention have a synergistic effect and include an anti-wear additive of formula X=P(OR) , where X represents an oxygen or a sulfur atom, and each R, which can be the same or different, represents a phenyl, tolyl or xylyl group, a halogenated derivative of such a group, tritolylÂphosphate, trixylylphosphate or triphenylphosphorothionate, the extreme pressure additive being an organic sulfide. |