The Subaru JDM 12mm Oil Pump has a higher flow rate when compared to the USDM 11mm and smaller oil pumps. The JDM Oil Pump is a must-have for those of you who plan on making more than 450 WHP and need the right amount of fuel flow to prevent oil starvation issues under high-RPM use. This oil pump is a direct replacement for your factory oil pump, and makes for an excellent upgrade for those of you who are rebuilding your engine.