Mishimoto Performance Aluminum Auxiliary Radiators for 2020-2026 BMW & Toyota (3.0L) - Pair

Fits select 2020-2026 BMW M340i, M440i, Z4, and Toyota GR Supra (3.0L).

Protect your high-performance B58 engine from heat soak with the Mishimoto Performance Aluminum Auxiliary Radiators. While the latest Supra and its BMW platform-mates are formidable track machines, high coolant temperatures can quickly trigger limp mode during aggressive driving. Mishimoto addresses this by replacing the thin factory cores and failure-prone plastic end tanks with a robust, full-aluminum TIG-welded construction designed for the street, track, or drag strip.

These auxiliary radiators feature a 1.57-inch (40mm) thick core, providing a 30% increase in core volume over the stock units. The optimized tube-and-fin design expands external fin surface area by 180%, significantly improving heat dissipation. To ensure long-term durability under high pressure, the core utilizes strutted tubes to prevent breaks and leaks. Sold as a pair with a polished finish, these radiators are a direct-fit upgrade for enthusiasts seeking reliable thermal management.

• Full aluminum, TIG-welded construction for maximum durability
• 1.57-inch (40mm) thick brazed aluminum core
• 30% increase in core volume over OE units
• 180% increase in external fin surface area
• Strutted tubes for enhanced core stability and leak resistance
• Polished finish for a clean engine bay aesthetic
• Includes Mishimoto Lifetime Warranty
• Manufacturer Part Number: MMRAD-SUP-20A