The CSF MK3 Ford Focus ST High-Performance All-Aluminum Radiator is engineered to eliminate the heat-soak issues commonly found in modified or aggressively driven Focus ST models. While the Focus ST is well-designed out of the factory, additional power, spirited driving, and hot climates can quickly push the stock cooling system beyond its limits. CSF’s high-performance radiator provides a significant cooling increase to keep temperatures stable under all conditions.

With over 50 years of cooling system manufacturing experience, CSF delivers a racing-inspired radiator designed for both daily driving and demanding motorsports environments. The 1-Row 31mm performance core features CSF’s exclusive B-Tube Technology, which uses a uniquely engineered “B” shaped tube instead of the standard oval “O” design. This stronger, thinner, and more efficient tube increases heat transfer surface area by approximately 15%, improving overall cooling capacity. Ultra-efficient multi-louvered fins further maximize airflow to reject heat as effectively as possible.

The radiator is a true drop-in fit, requiring no modifications. CNC-machined brackets, OE-style inlet and outlet connections, and fully TIG-welded all-aluminum construction ensure durability, strength, and long-term performance. The triple-pass flow configuration forces coolant through the core three times before exiting, delivering the lowest possible outlet temperatures and drastically improving thermal stability.

Compared to the factory single-row plastic-tank radiator, the upgraded CSF core offers increased thickness, larger fluid capacity, stronger materials, and significantly enhanced cooling performance—ideal for high horsepower builds, track use, and drivers who want to protect and extend the life of their EcoBoost engine. Whether you're pushing a race-engine setup or simply wanting to maintain reliable temperatures during spirited driving, this radiator provides the ultimate cooling solution.

Key Features:
• 1-Row 31mm ultra-high-performance aluminum core
• Triple-pass flow configuration for dramatically reduced outlet temperatures
• CSF exclusive B-Tube Technology for approximately 15% improved heat transfer
• 6.5mm tall multi-louvered fins for maximum airflow efficiency
• CNC-machined mounting pins and brackets
• OEM-style inlet and outlet for reuse of factory or aftermarket hoses
• 100% all-aluminum TIG-welded construction
• True plug-and-play drop-in installation with no modifications
• Each unit individually leak-tested and pressure-tested
• Backed by a 2-year limited warranty

Fitment 

• 2013–2018 Ford MK3 Focus ST Turbocharged 2.0L L4

CSF developed this radiator with leading EcoBoost specialists to address excessive coolant temperatures found in high-powered Focus ST builds. The result is a track-proven cooling upgrade now available to all Focus ST owners. Even moderate power increases or enthusiastic driving can benefit greatly from this system. For the most reliable, efficient, and durable cooling upgrade available, trust CSF’s racing-grade engineering.