Abstract: The changes in soot content, viscosity, mental content, total acid value, total alkali value, nitrification and phosphorus chemical state of eight kinds of engine oils in 500-hours Mack T-9 bench test were analyzed to investigate the effects on the cylinder liner wear. The results indicate that the diesel engine oil with steady viscosity, strong anti-oxidization ability and high total alkali value is useful to improve the anti-wear performance. The knowledge from the results is helpful to develop high-grade diesel engine oils.

Key words: diesel engine oil, Mack T-9 engine bench, anti-wear performance, physicochemical properties