Abstract: Filtration systems having a pressure differential sensor mounted on a bottom side of the filter housing are described. The pressure differential sensor engages with the removable filter cartridge to provide a seal between the clean side and the dirty side of the filter media when the removable filter cartridge is received within this housing. The pressure differential sensor is positioned such that it measures a pressure differential across only the removable filter cartridge.

Abstract: A filter cartridge having a bypass filtration media is described. The filter cartridge includes main filtration media. In some arrangements, the main filtration media includes first filtration media and second filtration media that has a different filtering efficiency than the first filtration media. The filter cartridge is configured to be installed in a filtration system having a bypass mode. While in the bypass mode, fluid passing through the filtration system is allowed to bypass the main filtration media. To avoid unfiltered fluid from passing from the inlet of filtration system to the outlet (e.g., and on to an internal combustion engine), the fluid flows through the bypass filtration media (e.g., during cold start conditions). In some arrangements, the bypass filtration media has a lower filtering efficiency than the main filtration media.