The purpose of this document is to recommended a number of standard methods with established repeatability and reproducibility, which are widely recognized and applied for used engine oil analysis and which should be used in the event of dispute on the oil condition. It is not the intention to promote these standard methods for routine analysis as they are often too elaborate, not automated and sometimes provide less information in comparison to some proprietary methods. This would lead to an uneconomic burden on industry and would be restrictive.