Filter Life versus Engine Wear

Filter evaluation methods using radioactive tracers have been developed which are capable of measuring the ability of new and used full flow lubricating oil filters to protect automobile engines from bearing wear. These methods determined that a large increase in wear rate is allowed by several types of commercially available filters when they have been used for relatively few miles on automobiles in typical use. This contradicts information obtained from standardized filter bench tests. The variables investigated include engine operating practices, dispersancy level of motor oil, amount and particle size of test contaminant, and effect of open relief valves.