
Lubrication of the engine parts is the vital function of an engine oil. The engine oil lubricates the engine parts for its efficient movement, thereby reducing the extent of metal contact, friction, and heat generation within the engine. In addition, cleaning & cooling the engine parts, sealing the gaps, and rust prevention are the other functions carried out by the engine oil. Engine oils are prepared by addition of substances, such as viscosity index improvers, antioxidants, metal detergents, and others to the base oil. The kind of oil used in vehicles varies depending upon the engine type.