| abstract |
The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an ashless antioxidant. The ashless antioxidant may be selected from phenolic compounds, aryl amine compounds, and sulfurized olefins, especially 2,6-hindered phenols and diarylamine compounds. |