Permanent Viscosity Loss of Viscosity Modifiers in Laboratory Bench Shear Tests
The API Lubricants Committee sponsored a New Category Development Team (NCDT) to oversee development of the new heavy duty diesel (HD) engine oil category PC-11. Due to reports from the field that some API CJ-4 oils were shearing out of grade in engines equipped with SCR after-treatment devices, the NCDT convened a Shear Stability Task Force (SSTF) in early 2012. The Task Force was charged with studying the issue and coming up with recommendations to ensure that PC-11 engine lubricating oils stay in grade.