Low Temperature Fluidity of Lubricating Oils Under Slow Cool Conditions

A Slow Cool Fluidity Test (SCFT) was developed to detect gelation of oils. In this test, SAE 10W multigrade oils of known poor field experience solidified at temperatures ranging from − 11 to − 17°C. The test was based on field temperature histories, and was found to be more reliable than other standard and experimental industry tests in detecting gelation tendencies. The SCFT consists of a 0.10° C per hour cool from above the oil's cloud point to the lowest use temperature expected. Fluidity is determined by the time for the oil to flow 30 mm when a standard ASTM pour point test jar is turned from vertical to horizontal. The effect of additives such as pour point depressant type and quantity can be determined by utilizing the SCFT.