Respondent Shell Oil Company is a corporation organized, existing and doing business under and by virtue of the laws of the State of Delaware, having its principal offices at One Shell Plaza, Houston, Texas 77002. VI improvers are synthetic rubber compounds, either polymers or styrenics, that are blended with refined oil to enhance the viscosity properties of the oil for use in motor oil. The viscosity of a fluid is its internal resistance to flow. The higher the viscosity, the more resistance to flow. Lubricating oils must have enough viscosity to maintain a film of the proper thickness on the surfaces that they are intended to protect.
Temperatures affect the viscosity of oil, higher temperatures lowering the viscosity.
Motor oil, which is used to lubricate the interior of an engine, must have sufficient viscosity to adhere to the internal surfaces of the engine even after the engine gets hot and reduces the oil's viscosity. At the same time, motor oil must have low enough viscosity to flow through the engine when the engine is cold, particularly in winter weather. Refined oil by itself does not have both the needed high viscosity when the engine is warm and the low viscosity when the engine is cold. An oil with low viscosity which will flow well at low temperatures will lack the required viscosity to protect the engine at high temperatures. An oil with a high viscosity which will protect the engine at high temperatures will not flow well at low temperatures.