Prior to understanding the viscosity index, we need to comprehend the physical property of fluids called “Viscosity”.

Here the question arises, What is Viscosity? Generally, Viscosity is the most important property for the lubricant and it can be defined as an oil’s resistance to flow and shear.

Taking a proactive approach to monitoring your lubricant’s viscosity can have a major effect on the health, and life of your machinery.