Development of a High Shear Rate Capillary Viscometer for Engine Oils

A high shear rate capillary viscometer has been developed. It is suitable for measuring the viscosity of engine oils at shear rates of 10⁵ to 10⁶ s⁻¹ and at temperatures to 150°C, conditions which are within the range experienced by oils in automobile engines. It has proven useful for evaluating the total shear stability of VI-improved oils and is also being used for interpreting laboratory engine friction testing.