This page contains information about the Viscosity analyte measured at 100° Celsius.
Viscosity at 100°C
Method: ASTM D445-10
Units: Centistokes
Viscosity is defined as a measure of a fluid's resistance to flow. The standard measure of this property for industrial lubricating oils is termed "Kinematic Viscosity".
There are two frequent causes for an increase in crankcase oil viscosity. Accumulation of combustion by-products (mainly Soot) which can "thicken" the oil. The second is heat, which can cause oxidation.
The two primary causes of viscosity decrease are fuel dilution and viscosity shear. Fuel dilution is not a failure of the oil, but a contamination problem which should be resolved promptly. Viscosity shear of the long chain polymer molecules indicates that the viscosity improvers in the oil may not be suitable for the application.
Variations in viscosity should be monitored to ensure adequate lubrication protection is being provided. Compartment transfers and top-up or service with incorrect viscosity oil are the most common causes of viscosity variation.