CSF 8258 42mm Auxiliary Radiator with Rock Guard for 2015-2021 BMW M2/M3/M4 (Left or Right)

Fits select 2015-2021 BMW M2 Competition/CS, M3, and M4 models (F8X chassis).

Engineered to replace the prone-to-failure factory units, the CSF 8258 Auxiliary Radiator provides a substantial cooling upgrade for high-performance street and track applications. CSF eliminated the weak OE plastic mounting pods in favor of a modular, 100% all-aluminum TIG-welded design that fits both the left and right sides of the vehicle. This design maximizes internal space, allowing for a 42mm 2-row high-performance core that offers a 6.4% increase in core size and a 10% increase in tank volume over stock.

Equipped with CSF’s exclusive B-Tube technology, these radiators optimize heat dissipation through increased surface area and improved airflow. To address common road debris punctures, this unit includes a detachable, integrated bolt-on rock guard for added protection. The satin black finish provides a durable, stealthy look behind the grilles, while the OE-style "quick connect" fittings ensure a true drop-in installation with no modifications required.

• Manufacturer Part Number: 8258
• Construction: 100% all-aluminum TIG-welded
• Core Architecture: 2-row 42mm core with B-Tube Technology
• Fin Height: 6.5mm multi-louvered design for maximum surface contact
• Fitment: Modular design fits both left and right sides (sold individually)
• Finish: Satin black for OEM+ appearance
• Included Hardware: Integrated detachable rock guard
• Testing: Individually leak and pressure tested
• Warranty: 2-year limited warranty