CSF's high-performance all-aluminum radiator is a direct drop-in upgrade for automatic-transmission BMW 135i, 335i, X1, and Z4 models, built for street and track use on higher-horsepower and race builds. It runs a 2-row 42mm dual core using CSF's B-Tube technology, which raises heat-transfer surface area by roughly 15% over conventional round tubes, with 6.5mm multi-louvered fins for maximum airflow. The radiator accepts all OEM components including the quick-connect hoses, AC condenser, mounting brackets, and fan shroud with no modifications.
| Type | High-performance all-aluminum radiator (CSF B-Tube) |
| Core | 2-row 42mm dual core |
| Fins | 6.5mm multi-louvered |
| Included | CNC-machined quick-connect inlet/outlet, all-aluminum race-style drain plug |
| Finish | Smooth satin |
| Fit | Automatic transmission; drop-in, accepts OEM hoses, AC condenser, brackets and fan shroud |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2008-2013 | BMW | 135i | Base |
| 2013 | BMW | 135is | Base |
| 2007-2013 | BMW | 335i | Base |
| 2013-2015 | BMW | X1 | sDrive28i |
| 2013-2015 | BMW | X1 | xDrive28i |
| 2012-2016 | BMW | Z4 | sDrive28i |
| 2009-2016 | BMW | Z4 | sDrive35i |
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.
