;Absolute Efficiency Efficiency is the filter's ability to capture contaminants. The more efficient a filter is, the more contaminants it will remove from the oil. AMSOIL Ea Oil Filters have one of the best efficiency ratings in the automotive/light-truck market. Ea Oil Filters provide a filtering efficiency in accordance with industry standard ISO 4548-12 of 98.7 percent at 20 microns, while competitive filters demonstrate efficiencies as low as 51 percent .Less Restriction Proper oil flow is essential to keeping engine parts lubricated at all times. AMSOIL Ea Oil Filters' synthetic fibers are smaller than the fibers used in traditional filters, allowing Ea Oil Filters to provide lower restriction. During cold-temperature warmup periods, an Ea Oil Filter allows the oil to flow through the filter more easily than a typical cellulose filter does. Lower restriction decreases engine wear.