CSF 8258 High-Performance Auxiliary Radiator for 2015-21 BMW F8X

Vehicle Fitment

• 2015-2018 BMW F80 M3 (incl. CS & Competition, S55)
• 2015-2020 BMW F82/F83 M4 (incl. CS, GTS & Competition, S55)
• 2019-2021 BMW F87 M2 Competition (S55)

Features

• High-performance auxiliary radiator upgrade for F8X platform
• 2-row 42 mm core with advanced B-Tube cooling technology
• Ultra-efficient 6.5 mm tall multi-louvered fins for superior heat transfer
• Modular design fits left or right side - one part fits both
• All-aluminum TIG-welded construction for durability
• OEM-style quick-connect inlet and outlet for easy install
• Includes detachable rock guard for impact protection
• Drop-in fitment with no vehicle modifications required

Specifications

• Core design: 2-row high-performance auxiliary radiator
• Core thickness: 42 mm
• Fin height: 6.5 mm multi-louvered fins
• Material: 100% all-aluminum
• Installation: OEM drop-in style
• Finish: Satin black for an OEM+ look
• Sold individually - two units recommended per vehicle

Included Components

• 1x CSF 8258 auxiliary radiator
• 1x Detachable rock guard

Product Description

The CSF 8258 High-Performance Auxiliary Radiator is engineered to upgrade and supplement the factory cooling system on BMW F8X M-series vehicles equipped with the S55 turbocharged inline-6 engine. Featuring a 2-row 42 mm core with B-Tube technology and tall multi-louvered fins, this radiator improves heat dissipation and coolant flow compared to stock auxiliary radiators, helping maintain lower operating temperatures during spirited driving or high-load track sessions.

Designed as a drop-in fit with OEM-style quick-connect fittings and a modular design that can be installed on either the left or right side, the CSF 8258 installs easily without modifications. Its all-aluminum TIG-welded construction and included detachable rock guard enhance durability and protection from road debris. Sold individually, it's recommended to install a pair for full cooling system balance and maximum performance under both street and track conditions.