From Russia with Love. Amsoil 0w20 SP subjected to the d7109. If I'm reading this right, after 90 cycles the kv 100C went from 8.92 to 8.69, which is an excellent result.
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"This test method is not intended to predict viscosity loss in field service in different field equipment under widely varying operating conditions, which may cause lubricant viscosity to change due to thermal and oxidative changes, as well as by the mechanical shearing of polymer. However, when the field service conditions, primarily or exclusively, result in the degradation of polymer by mechanical shearing, there may be a correlation between the results from this test method and results from the field."
Standard Test Method for Shear Stability of Polymer-Containing Fluids Using a European Diesel Injector Apparatus at 30 Cycles and 90 Cycles
Significance and Use 5.1 This test method evaluates the percent viscosity loss of fluids resulting from physical degradation in the high shear nozzle device. Thermal or oxidative effects are minimized. 5.2 This test method may be used for quality control
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Shear Stability and Viscosity Loss
Shear stability is an important aspect of lubrication. Three of the common instruments used to permanently shear-degrade lubricants are the Kurt Orbahn or Bosch Injector, Sonic Shear, and KRL (tapered roller bearing).
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"This test method is not intended to predict viscosity loss in field service in different field equipment under widely varying operating conditions, which may cause lubricant viscosity to change due to thermal and oxidative changes, as well as by the mechanical shearing of polymer. However, when the field service conditions, primarily or exclusively, result in the degradation of polymer by mechanical shearing, there may be a correlation between the results from this test method and results from the field."
