The Mishimoto MMRAD-F80-15A Performance Auxiliary Radiator is designed for 2015–2020 BMW F8X M3 and M4 models equipped with the S55B30 engine. It replaces the factory auxiliary radiator with a larger, fully aluminum unit engineered for improved cooling capacity during sustained high-load driving, aggressive street use, and track sessions.
Mishimoto increased core volume by 9% and external tube area by 32% compared with the factory auxiliary radiator, helping the system reject more heat into the airstream. The radiator uses TIG-welded aluminum end tanks, internally reinforced strutted tubes, and a removable powder-coated steel stone guard for added durability in the low-mounted factory radiator location.
Features
- Mishimoto performance auxiliary radiator
- Direct fit for 2015–2020 BMW F8X M3 and M4
- Designed for the S55B30 engine
- 9% more core volume than the factory auxiliary radiator
- 32% more external tube area than stock
- Full aluminum construction
- TIG-welded aluminum end tanks
- Strutted internal tubes for added strength and vibration resistance
- Removable powder-coated steel stone guard
- Fits either driver-side or passenger-side auxiliary radiator location
- Installs in the factory location with no cutting, fabrication, or adapter work required
- Designed for sustained high-load and performance driving
Fitment
- 2015–2018 BMW M3 Base Sedan
- 2015–2020 BMW M4 Base Coupe
- 2015–2020 BMW M4 Base Convertible
- 2016 BMW M4 GTS
- 2018–2020 BMW M4 CS
- 2019–2021 BMW M2 Competition
- 2020–2021 BMW M2 CS
Compatible with S55-powered BMW M2, M3, and M4 applications listed above. Verify exact year, trim, chassis, and cooling-system configuration before ordering.
This radiator is designed for compatible BMW F80, F82, and F83 chassis applications and can be installed in either auxiliary radiator position.
Specifications
- Manufacturer: Mishimoto
- Part Number: MMRAD-F80-15A
- Product Type: Performance Auxiliary Radiator
- Vehicle Platform: BMW F8X M3 / M4
- Engine Code: S55B30
- Chassis Codes: F80 / F82 / F83
- Material: Aluminum
- Core Rows: 1
- Overall Length: 10.4 Inches
- Overall Height: 9.9 Inches
- Overall Width: 3.3 Inches
- Core Length: 10.1 Inches
- Core Height: 6.9 Inches
- Core Thickness: 1.6 Inches
- Drain Plug Thread: M12 x 1.5
- Core Volume Increase: 9% Over Stock
- External Tube Area Increase: 32% Over Stock
Enhanced Cooling Capacity
The MMRAD-F80-15A uses a larger core than the factory auxiliary radiator, increasing coolant volume and external tube area. Mishimoto designed this additional capacity to provide more thermal headroom during repeated high-load driving where the factory unit can become heat-soaked.
Reinforced Aluminum Construction
The radiator replaces the factory plastic end-tank design with aluminum TIG-welded end tanks. Internally strutted tubes reinforce the core against vibration and impacts that can affect a low-mounted auxiliary radiator over time.
Driver or Passenger Side Installation
A single MMRAD-F80-15A radiator can be used in either the driver-side or passenger-side auxiliary radiator location. Mishimoto's bracket design allows the same part number to service either side of the vehicle.
Stone Guard Protection
The included removable powder-coated steel stone guard helps protect the exposed radiator core from gravel, road debris, and other impacts at the front of the vehicle.
Recommended Use
- Track-driven BMW M3 and M4 applications
- Performance street builds
- Modified S55B30 engines
- Vehicles experiencing elevated cooling demand during sustained high-load driving
- Replacement of a damaged or aging factory auxiliary radiator
What’s Included
- 1 Mishimoto MMRAD-F80-15A auxiliary radiator
- 1 powder-coated steel stone guard
- 2 powder-coated steel mounting brackets
- 3 O-rings
- 8 M6 lock washers
- 8 M6 button-head bolts
Installation
The radiator installs in the factory auxiliary radiator location with no cutting, fabrication, or adapter work required. Mishimoto rates installation difficulty as easy. Verify all O-rings, coolant connections, brackets, and hardware are installed correctly, then refill and bleed the cooling system according to the BMW service procedure.
Proposition 65 Warnings.
Cancer and Reproductive Harm. See details below.
Items that are not CARB Legal will not be sold and ship to California or CARB states.
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