CSF High Performance Radiator for MK3 Ford Focus ST

The MK3 Focus ST earned a strong following thanks to its sharp styling, responsive chassis, and capable 2.0 L EcoBoost engine. As these cars continue to be enjoyed on the street and pushed hard on track, cooling demand has increased. The CSF High Performance Radiator offers a major improvement in coolant temperature control, making it a valuable upgrade for both daily driven and modified Focus ST models.

Design and Engineering

CSF collaborated with EcoBoost specialists to develop a radiator capable of addressing the high coolant temperatures seen in tuned and track focused builds. The result is a premium cooling solution engineered for maximum efficiency, durability, and perfect fitment. Even lightly modified cars or those driven in hot climates can benefit from the improved thermal stability this radiator provides.

CSF vs OEM

The factory radiator uses plastic end tanks and a single row aluminum core, suitable for normal use but not ideal for heat intensive applications. The CSF unit replaces this with a full aluminum construction featuring a 31 mm high performance core. Increased thickness and fluid capacity allow the system to absorb and shed heat far more effectively.

CSF’s exclusive B Tube technology increases heat transfer by around 15 percent when compared with standard oval tubes. Multi louvered fins further enhance efficiency by maximizing airflow through the core. Combined with TIG welded aluminum tanks, the radiator offers increased strength, reliability, and long term durability.

Triple Pass Flow Advantage

The CSF radiator incorporates a triple pass flow design that routes coolant through the core three times before exiting. This configuration reduces outlet temperatures, minimizes hot spots, and ensures stable cooling under sustained load. The result is more consistent performance during spirited driving and track sessions.