When judging a filter manufacturer’s efficiency claims, it’s important to make sure that the dust used in their testing is representative of the most harmful contaminant size. Many filter companies use course dust which will produce greater efficiency figures; however it’s the small dust particles that cause the greatest damage. At AEM we perform filtration efficiency testing using ISO 5011:2000(E) test standards using fine “A-2” test dust. Today’s engines are manufactured with very close and precise tolerances in order to control hydrocarbon (Hc) emissions, have reduced friction and produce high specific power. AEM is involved with filter development for many of the vehicle manufacturers and virtually ALL of them require that filtration efficiency testing be done using ISO A-2 Fine dust. For more information, visit the SAE website where you can download numerous technical papers written on air filtration. Learn more here…