Some Effects of Crankcase Lubricant Viscosity on Engine Operation

Abstract

<div class="htmlview paragraph">Stricter control of crankcase - oil viscosity specifications at both low and high temperatures is needed to assure optimum engine starting performance, operating economy and durability.</div> <div class="htmlview paragraph">The degree of improvement made by petroleum refiners in low temperature cranking and starting characteristics of a number of major brand crankcase lubricants is shown by a comparison of 1966 vs 1962 test data.</div> <div class="htmlview paragraph">High temperature viscosity also is important because of its effects on oil economy, hydraulic valve lifter collapse and hot engine starting.</div>