EFFECT OF OIL COMPOSITION ON POUR REVERSION IN ALASKA AND BRITISH COLUMBIA

Past experience showed that laboratory cycles available seven years ago for predicting stable pour points of engine lubricating oils did not correctly predict maximum field pour points. Additional information on factors influencing fluidity of lubricants during field exposure was necessary for lubricant development. This information was gained by the exposure of engine lubricating oils to winter temperatures at Prince George, B.C., and Fairbanks, Alaska. Variables in base oils, lubricating oil additives, and pour depressants which influence stable pour point are discussed. All components influence stable pour point. Correlation of field stable pour points with several laboratory cycles is reviewed. With the better cycles stable pour point can be predicted within ± 10°F of the maximum field stable pour point 50% to 70% of the time. Experience gained is applied to the development of lubricants of low field stable pour point.