Study on comprehensive degradation stability of special and nonspecific motor oils

In order to study the degradation characteristics of special and nonspecific motor oil, two experimental vehicles carried out eight road tests with four types of oils, which two types of oils were special oils for its engines recommended by OEM (original equipment manufacturer) and the other two types of nonspecific oil were bought from market. Total acid number, oxidation stability, oxidation, nitration and sulfation values of experimental oils were analysed. The interpolation method and Euclidean distance were used to evaluate the similarity of change curves of oil properties. The results show that the oxidation onset temperature had good similarity both in special oils and nonspecific oils. The sulfation value of nonspecific oils had highest change rate of Euclidean distance. The change rate of Euclidean distance of two special oils were less than 8.48%, which had more stability than that of the nonspecific oils. This work can serve as a reference for end users to select motor oils and oil developers to improve the oil stability.

Automated summary

The study found that special oils and nonspecific oils had good similarity in oxidation onset temperature, but nonspecific oils showed the highest change rate in sulfation value. The change rate of Euclidean distance of two special oils was less than 8.48%, indicating greater stability compared to nonspecific oils. This research can be a valuable reference for end users in selecting motor oils and for oil developers in improving oil stability.