Oils

The first attempt to classify or identify engine oils was made when appeared an automobile. Even at that time was known that viscosity is one of the most important oil characteristics. Depending on viscosity oils are divided into 3 types  –  law-viscous, medium-curing and heavy. Where instruments for exact viscosity determination was invented, Society of Automobile Engineers invented system of classification, based on such   measures. This system (Classification of engine oils viscosity –SAE J300) has eleven separate classes and marks of engine oil viscosity: SAE 0W, SAE 5W, SAE 10W, SAE 15W, SAE 20W, SAE 25W, SAE 20, SAE 30, SAE 40, SAE 50, (for transmission oils are used other marks of viscosity).