Oil filters play a major role in the performance and longevity of an engine by removing contaminants and promoting proper oil flow. Modern engines introduce more contaminants into oil than their predecessors. To compound the issue, oil sumps are shrinking, leaving fewer detergents and dispersants to help fight the by-products of the internal combustion process. An oil filter’s capacity must improve to contend with the additional contaminants. Capacity refers to the amount of contaminants a filter can hold while still remaining effective. To understand the significance of capacity, it’s helpful to know the basics of oil filtration. Clean oil is vital to keeping engines running properly. The oil filter must remove contaminants introduced into the oil and prevent them from reaching sensitive engine parts without restricting normal oil flow. Internal sources of contamination include wear products from the rubbing surfaces of the engine, and degradat...