✔️ Engine oil classification and engine oil quality

Motor oil: Western advanced countries, especially the United States, have prepared and supplied motor oil standards since the 1950s. Other countries have either directly used those standards or used their national codes to introduce the said standard. In America, three institutes, API, SAE, and ASTM, have been responsible for the preparation of standards in cooperation with each other. The mentioned standards were introduced with signs (SAE indicating oil viscosity) and signs (API for oil quality and efficiency). The US Army and the British Army also introduced their desired special standards with MIL-L and Def-Stan marks using SAE and API standards. European countries, like other countries of the world, used American standards, but since the 1970s, these standards were introduced under the mark (CCMC of the European Committee of Automobile Manufacturers). This committee was later renamed to ACEA. On the other hand, car manufacturers in America and Japan were dissatisfied with the lack of speed of API, SAE, and ASTM in developing the standards they needed for engine oil, so they developed a new standard called ILSAC. In addition to the mentioned organizations and institutions, large and reliable automobile manufacturing companies also have their own special standards. For example, Mercedes-Benz in Europe and Mack in America are among these companies.

This grading is purely based on viscosity. Due to the importance of viscosity, the SAE Society of Automotive Engineers has based the classification of motor oils on this characteristic, so that two groups of viscosity are defined in this system. One group has the letter (Winter) W and the other group is without the letter W. The higher the SAE number, the higher the viscosity of the corresponding oil. The letter W along with the SAE number represents oils that are used in cold environments and the viscosity of these oils in heat is not important. Oils that do not have the letter W in front of them are used in warm environments and their viscosity is not important in the cold. The base temperature for the cold environment is -18 °C and for the hot environment it is 100 °C. The oils listed in the table are single grade. Metal balls with the same weight in oils with different viscosity according to the SAE standard, motor oils are classified in the following two general categories in terms of viscosity changes: Mono grade oils Multi grade oils The oils mentioned above were examples of single grade oils. Multi-grade oils, due to the presence of special additives, act like low-viscosity oils (10 and 20) in the cold (when starting the engine), and when the engine warms up, their viscosity increases to the viscosity of oils with a higher viscosity of 40 to 50. arrive Multigrade oils are obtained by mixing an appropriate percentage of a low viscosity oil with viscosity index improving polymers. For example, SAE 10W40 oil acts like SAE10W oil at low temperatures of -18ºC, but at 100ºC it acts like SAE 40W viscosity oil.

This organization has defined and classified oils based on their viscosity at 40ºC in terms of centistock c.St and in industrial cases such as Turbine oil and hydraulic devices, etc. are used.