Generation of engine oils with defined degree of degradation by means of a large scale artificial alteration method

Abstract A novel artificial alteration method was developed to generate altered engine oils with defined degradation degree in large amounts. The final oil condition was selected based on a field study of used oils from conventional passenger cars. Additionally, comparison with a standardised small scale method was performed. Oil condition was regularly monitored throughout the artificial alterations by conventional and advanced analytical methods. Generally, very good comparability regarding conventional oil parameters, i.e., additive depletion, acidity, total base number, elements, and water, was found between small scale, large scale and field. It was demonstrated that advanced analytical methods helped to overcome shortcomings of conventional condition monitoring by providing knowledge on degradation products on the molecular level, in particular those from antiwear additive.