Conventional practice is for automotive engine lubrication filter designers to include many devices in a typical “spin-on” filter. These include the filter element housing, tapping plate, and internal components, such as, an anti-drainback valve, the filter element structural support, the filter media and in some cases, the safety relief valve. Understanding the interaction of all these components before a prototype is built greatly aids in achieving a functional, cost effective solution to meet required flow and pressure drop, filtration efficiency, and contaminant capacity requirements for a particular filter. Furthermore, the investment in modeling a specific filter design enables variations or modifications to be made to the original design very easily and at little cost.This paper presents a detailed mathematical flow model that was developed for a new type of dual flow filter. A fluid flow resistance model was developed for each component of the new filter design using measured pressure-flow data. The basic orifice flow equation was used to define flow coefficients for the model, and example calculations are provided.