CSF Aluminum Radiator for BMW E46 3-Series/Z4 2-Row Core B-Tube Tec

CSF Aluminum Radiator for BMW E46 3-Series / Z4 — 2-Row Core with B-Tube Technology Upgrade cooling performance for your BMW E46 3-Series or Z4 with the CSF all-aluminum radiator. Built from over five decades of radiator engineering, this high-performance unit is designed for street driving, high-horsepower builds, and track use. Application: BMW E46 3-Series & Z4 Core: 2-row all-aluminum core Technology: Exclusive CSF B-Tube design for improved strength and heat transfer The patented B-Tube shapes increase tube surface area by ~15% compared to traditional oval tubes, enabling dual liquid laminar flow and the cooling capacity of two smaller tubes within the same footprint. Because B-Tubes are seam-brazed and inherently stronger, CSF can use thinner, lighter aluminum for superior thermal efficiency and reduced weight. Precision-engineered multi-louvered fins and application-specific fin spacing are optimized in CSF's wind-tunnel lab to maximize airflow and heat rejection. The result is consistent operating temperatures, improved reliability under sustained load, and better protection for high-output engines. Why choose this radiator? Enhanced cooling efficiency, lightweight construction, motorsport-proven design, and direct-fit compatibility for your E46/Z4 — a straightforward upgrade to keep your BMW running cooler and safer.