Pour-Point-Stability Characteristics of Winter-Grade Motor Oils 480171
ANALYSIS of winter field storage test data on winter-grade oils containing pour depressants leads to identification of the basic features of the temperature cycles which result in severe pour reversion.
The pour-stability test developed on the basis of the analysis exposes oils to a 6-day temperature cycle in a laboratory refrigerated cabinet. Two different cycles are used, one for oils of high cloud point and the other for oils of intermediate or low cloud point. Test results agree well with field observations for winter-grade motor oils, heavy-duty oils, and diluted heavy-duty oils.