CSF High-Performance auxiliary radiator for the BMW G8X M2, M3 and M4. Its TIG-welded aluminum tanks are larger than the OE plastic units for more strength and fluid volume, and a 2-row 42mm core with CSF's exclusive B-Tube technology and 5mm fins increases cooling capacity and recovery. It is a true drop-in that fits both the left and right side, uses OEM-style quick-connect fittings, and includes a detachable rock guard. Sold individually; all applications use two auxiliary radiators.
| Type | High-performance auxiliary radiator (CSF B-Tube) |
| Core | 2-row, 42mm |
| Fins | 5mm multi-louvered |
| Material | All-aluminum, 100% TIG-welded tanks |
| Inlet / Outlet | OEM-style quick-connect |
| Fit | True drop-in; fits both left and right side |
| Finish | Satin black |
| Included | Detachable rock guard |
| Warranty | 2-year limited warranty |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2024-2025 | BMW | M3 | Competition xDrive |
| 2024 | BMW | M3 | CS |
| 2021-2026 | BMW | M4 | Base |
| 2021-2026 | BMW | M4 | Competition |
| 2022-2026 | BMW | M4 | Competition xDrive |
| 2025 | BMW | M4 | CS |
| 2023 | BMW | M4 | CSL |
Shipping: In-stock orders placed before 3 PM EST ship the same day, and everything else ships within 24 hours. Standard, expedited, and overnight options are available at checkout. Backordered items ship as soon as we get them back in stock. Contact us for lead times. See the full Shipping Policy.
Returns: 30-day returns on new, unused items in original packaging. See the full Refund Policy.
