Semigraphical Method of Motor Oils Thermal-Oxidative Stability Index Control

At present, it is impossible to establish the effect of temperature on the aging processes of motor oils, base oil base, and additives without experimental studies. In this article, the research methodology and experimental results of thermooxidation stability indicators including the optical density, volatility and thermal oxidation coefficient of Texaco Extra 10W-40 SL/CF motor oil are presented. The thermal and oxidation stability of the oil under investigation was determined from the change in optical density and evaporation. An analytical relationship between the thermooxidation stability and the test temperature was established, on the basis of which a graphoanalytical model for predicting these parameters at other test temperatures was proposed. The use of this method of research is aimed at determining such performance indicators for the quality of motor oils as the temperature of the beginning of the processes of transformation in oil and the critical temperature of these processes, which determine the temperature range of its efficiency. The proposed performance indicators will allow one to compare lubricants and identify them for compliance with the groups of operational properties.