Full synthetic lubricants are expensive because of their excellent performance. The price of full synthetic lubricants is about 5 times that of mineral oil. One of the easiest ways to identify full synthetic air compressor oil is to look at its pour point.
The pour point of fully synthetic air compressor oil can reach -50~-40℃, while the pour point of mineral oil and semi-synthetic oil can only be about -20℃. Of course, the properties of lubricating oil ultimately depend on the composition of its base oil.