ABSTRACT
Presently, the global consumption of lubricants is approximately 37.4 million tons, in which the automotive sector consumes major amount of lubricants (almost 68%) and the rest 32% consumed by other industries. This 32% lubricants include 12% hydraulic oils, 15% metalworking and cutting fluid, 3% greases, and 2% gear oil. In automobiles, the engine is the most important component, and it requires continuous lubrication for smooth functioning. Engines consist of cylinder, piston, piston ring, connecting rod, gudgeon pin, crank, crankshaft, crankpin, inlet valve, exhaust valve, cam, and follower. During the movement engine part, it undergoes higher friction, resulting in less efficiency. The role of lubrication is not only to lubricate the engine parts, but it also helps to transfer the heat from the engine cylinder to the oil sump. The lubricant forms a sacrificial thin film layer in between the sliding surface of engine that prevents them from contact and reduces the wear. Further, gear and bearings are other automobile parts that undergo high pressure and wear.
