SEDL / STP / STP1068-EB / STP23001S

Co-ordinating European Council (CEC) Contribution to the Measurement of High-Temperature, High-Shear-Rate Viscosity and Its Relationship to Engine Operation

Vickars, MA
Scientific associateChairman, Esso Petroleum Co. Ltd., Esso Research Centre, Abingdon, Oxfordshire

Bates, TW
Principal scientistChairman, Shell Research Limited, Thornton Research Centre, Chester,

Pages: 9    Published: Jan 1989

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Abstract

Co-ordinating European Council (CEC) studies showed good agreement among results obtained with different types of high-shear viscometers. Curve-fitting procedures based on the Extended Cross Equation provided a means of comparing results from different viscometers and permitted the interpolation and extrapolation of viscosities to a standard temperature and shear rate, for example, 150°C and 10⁶ s^-1. These studies contributed significantly to the development of the first low-cost, commercial, rotational viscometer capable of measuring viscosity over appropriate temperature and shear rate ranges. Satisfactory precision was demonstrated, and international standard procedures were established for the Ravenfield viscometer. Engine studies showed strong linear correlations of high-temperature, high-shear (HTHS) viscosity with engine friction, engine-bearing oil flow, and fuel saving. Results of engine wear tests, however, did not appear to be viscosity dependent. Areas for future study, for example, measurement of bearing oil film thickness, are indicated, and the interaction of CEC with the European Committee of Common Market Automobile Constructors (CCMC), ASTM, and the Society of Automotive Engineers (SAE) is described.