1.1 ,This test method covers the determination of the rotational viscosity and the shear thinning properties of heavy duty diesel engine drain oils at 100 ,°,C, in the shear rate range of approximately 10 ,s^-1 to 300 ,s^-1, in the shear stress range of approximately 0.1 ,Pa to 10 ,Pa and the viscosity range of approximately 12 ,mPa·,s to 35 ,mPa·,s. Rotational viscosity values can be compared at a shear rate of 100 s^-1 by this test method.2^,3