CSF Racing Automatic Transmission Oil CoolerBMW G8X M3 M4 ZF8 High Performance Automatic Transmission Cooler The engineers at CSF know cooling. So when it comes to keeping your transmission temps down as you push your BMW G8X M3 M4 hard on the street or track, the CSF ZF8 Trans Cooler is the obvious choice. With an increase in cooling efficiency of around 30%, you can drive with confidence knowing you won't be damaging your expensive transmission due to overheating. The CSF #8221 Cooling