Gas-fuelled engine lubricating oil compositions

摘要

A gas-fuelled engine lubricating oil composition that is substantially free from anti-oxidant additives. The gas-fuelled engine lubricating oil composition exhibits good resistance to oil oxidation and nitration and improved corrosion resistance. The composition includes:(i) an oil of lubricating viscosity;(ii) a detergent composition including at least one calcium salicylate having a TBN in the range from 70 to 245;(iii) 0 to 0.2 mass % of nitrogen, based on the mass of the oil composition, of a dispersant; and(iv) a minor amount of one or more co-additives.