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The Cannon High Temperature High Shear (HTHS) capillary viscometer is currently used in the ASTM D4624 procedure to measure the viscosity of polymer containing lubricants at 150°C and shear rate of 106 sec-1. An expansion of the utility of this Cannon instrument is described in this paper to cover the temperature range of lubricants from 35 to 175°C and shear rates of up to 106 sec-1. A finite difference model is used to solve the transport equations for capillary flow at each temperature. The solution accounted for temperature, pressure, non-Newtonian and kinetic energy effects on viscosity. Fitting these data to a double truncated power law model provides the incipient non-Newtonian shear rate γ̇1, the power law index n, and the incipient second Newtonian shear rate γ̇2. All these parameters can be measured at temperatures of around 100°C or less. The n and γ̇2 were found to be regular functions of temperature while γ̇i is always in the measured range.