As a follow up to earlier publications, this paper reports on recent work carried out in Europe, within CEC, in the field of high shear reology aimed at defining a simple method to measure viscosity as seen by the engine. Seven SAE 15W–50 calibration oils were tested in a large number of high shear viscometers, engine tests and rigs in order to determine if any correlation was possible.
The work has shown that the low shear viscosity does not correlate with the behaviour of the oil in the engine and that the viscosity under high shear conditions is from 70 to 90% of the low shear viscosity. Correlation was found between high shear viscometers and power loss/oil-flow in engines.
Further work on lower viscosity oils is underway.