Development of Mini-Rotary Viscometer Measurement Techniques for Highly Sooted Diesel Engine Oils
In 1999 the ASTM Low Temperature Rheology of Used Engine Oils or LOTRUO task force was formed within Subcommittee D02.07 to address potential method and measurement issues for low temperature rheological determinations of used engine oils. A primary focus of this task force was to assist the heavy duty engine oil classification panel which was developing the new PC-9 category, to include a used oil pumpability specification from one of the new multicylinder EGR diesel engine tests. With anticipated soot loadings of 5-10% in some of these used oils, there was concern that standard ASTM test methods developed for fresh oil pumpability might not be suitable for these sooted oils. The task force conducted some preliminary work on a used Mack T8E test sample of approximately 5% soot loading. These data indicated that variation in preheating conditions could have significant influence on the low temperature properties measured by standard procedures.