The principal function of the engine oil lubricant is to extend the life of moving parts operating under many different conditions of speed, temperature, and pressure.

At low temperatures the lubricant is expected to flow sufficiently in order that moving parts are not starved of oil. At higher temperatures they are expected to keep the moving parts apart to minimize wear. The lubricant does this by reducing friction and removing heat from moving parts.

There are a various combinations of additives are used in engine oil to meet the required perfmance leve. The most important are listed below :

The total base number (TBN) indicates its acid-neutralizing ability and is expressed as mg KOH/g of additive.

TBN determines how effective the control of acids formed will be during the combustion process. The higher the TBN, the more effective it is in suspending wear-causing contaminants and reducing the corrosive effects of acids over an extended period of time.

API Service Symbol

The API (American Petroleum Institute) shows you the performance level. The first letter indicates the vehicle fuel type that the oil is designed for. "S" (Service) are intended for Gasoline engines. "C" (Commercial) are for Diesel engines. The second letter designates the quality level of the engine oil. The higher the letter, the more advanced the oil. Refer to Engine Oil Guide. The SAE (Society of Automotive Engineer) Viscosity Grade. The measure of an oil’s thickness and ability to flow at certain temperatures.