An Automated Fuel Injector Shear Stability Tester

The automated Fuel Injector Shear Stability Tester, a simple mechanical bench test for evaluating shear stability of polymer-containing oils, is described. Its advantages include unattended operation, fast, repeatable results, relatively small sample size requirement, and availability of several levels of shearing severity. The test shows good agreement with viscosity loss due to shear for various polymer types in a motored engine and in field tests of automotive crankcase oils. Good correlation with road test data for automatic transmission fluids is also shown.