As Gen 1 B58-powered BMWs in the F3X and F2X platforms have racked up miles and dropped in price, they’ve become go-to choices for tuners, track-day enthusiasts, and weekend warriors alike. With aging factory components and a growing number of owners modifying these cars, demand for motorsport-grade performance parts has surged. For those looking to push their Gen 1 B58 to the limit, upgrading the cooling system has quickly become a top priority.

CSF, the industry leader in high-performance BMW cooling, is the top choice for F3X and F2X owners who want more than just OEM reliability. Whether you’re building a serious track machine or simply want a bulletproof upgrade, the new CSF High-Performance Radiator delivers unmatched durability and cooling efficiency for your Gen 1 B58 BMW.

Design & Engineering

CSF has built a reputation for producing the best B58 cooling systems on the market. Backed by years of experience and input from customers, race teams, and development partners, CSF leads the industry in Gen 1 B58 cooling technology.

As more enthusiasts push the performance limits of F-Chassis BMWs, the factory radiator has started to show its age. Increased boost and upgraded turbos generate significantly more heat, and the stock system can struggle to keep up. Combined with the heat exchanger mounted in front of the radiator, engine coolant temps can get too hot, especially during track use which can trigger limp mode.

On top of that, OEM plastic radiators degrade over time. With clogged tubes, damaged fins, and a higher risk of cracked tanks or gasket failure, replacing the stock radiator becomes essential for long-term reliability and performance.

Key Design Features:

• 20–25% increase in heat transfer efficiency using CSF’s exclusive 5mm fin technology
• Improved cooling performance to support high-boost, big-turbo builds
• All-aluminum construction for superior durability over OEM plastic tanks
• Designed to work seamlessly with factory or aftermarket heat exchangers

Whether you’re building a street sleeper or prepping for your next track day, CSF’s Gen 1 B58 Radiator is engineered to handle the heat and then some.

CSF vs OEM

The original OE radiator from BMW is a plastic tank with a single row aluminum core design. While this is generally accepted as good quality and durable, there is always room for improvement. The 4.5mm fins on the OE radiator made the system fairly efficient for a factory unit. The core itself is one of the biggest limiting factors at only 34mm thick and a single cooling row.

The CSF radiator features the latest 5mm fin technology. These fins significantly increase the heat exchange surface area improving overall cooling efficiency and recovery while still maintaining good airflow. The core is much larger than the factory featuring 2-Row 42mm aluminum core. This both increases the fluid capacity of the radiator, and improves the cores ability to dissipate heat. CSF’s Exclusive B-Tube Technology increases the heat transfer by approximately 15% over regular oval welded tubes. In addition, the super-efficient multi-louvered fins maximize airflow through the core for the best possible performance.

The TIG-Welded 100% All Aluminum construction increases the overall strength of the radiator. This improves durability and longevity so you can be confident it will hold up to hard driving conditions. The CSF radiator mounts in the factory location and requires no modifications or cutting.

5mm Core Upgrade

While the 6.5mm fin version performed extremely well in testing, CSF always seeks to offer the ultimate cooling solution. Before going into final production the design was updated to incorporate CSF’s latest 5mm fin technology which was introduced at the end of 2023. This new core specification offers even more heat transfer area and thermal efficiency than the tested prototypes. CSF is confident this radiator is ready to take on the most demanding racing conditions in the world.

• 2-Row – 42mm Ultra-High-Performance Core
• Cooling Tubes with CSF’s Exclusive B-Tube Technology
• New 5mm Tall Ultra Efficient Fins with a Multi-Louvered Design for Maximum Surface Area Contact
• CNC Machined Mounting Brackets and OEM Style Inlet/Outlet
• 100% All Aluminum TIG-Welded Construction
• Hand Brushed Satin Finish
• True Plug-and-Play “Drop-in Fit” Installation Requires Absolutely No Modifications
• Individually Leak and Pressure Tested
• 2-Year Limited Warranty

• Applications:
  • 2016-2019 BMW F3X 340i (incl. xDrive)
  • 2017-2020 BMW F3X 440i (incl. xDrive)
  • 2017-2021 BMW F2X M240i (incl. xDrive)
  • 2017-2019 BMW F3X 330i w/ M Sport Package (incl. xDrive)
  • 2017-2020 BMW F3X 430i w/ M Sport Package (incl. xDrive)
  • 2017-2020 BMW F2X 230i w/ M Sport Package (incl. xDrive)

• OEM Part Numbers:
  • BMW: 17118482623