CSF Race-Spec Oil Cooler 11-16 F20 135i(X)(N55) 11-16 F21 M135i(X)(N55) 12-16 F22/F23 M235i(X)(N55) 11-15 F30/F31 335i(X) & Hybrid 3 (N55) 12-16 F34GTInnovative 2 Core In Series System Secondary In Series Backside Cooler has an Additional 5 Rows of Cooling for an ~40% Increase in Heat Rejection Made with CSF's AC Condenser Technology Using a 1 Row Super High Pressure 26mm Multi Channel Microtube High Density Multi Louvered Fin Design for Maximum Surface Area Contact Converted to a Single Pass Design with High Pressure Return Line for Optimal Flow "Drop In Fit" Requiring No Modifications to Install