The 2015-2020 BMW F8X M3 and M4 rely on auxiliary radiators mounted low in the front corners of the car to keep the S55 in its operating window. Under sustained track use and aggressive street driving, the factory units run out of cooling capacity and heat-soak between runs - and their low position leaves them exposed to road debris and the plastic end tanks prone to cracking under repeated heat cycling. The Mishimoto Performance Auxiliary Radiator replaces the stock unit with a larger, fully reinforced aluminum core engineered to add thermal headroom and survive the conditions that retire the OEM part early.----The core carries 9% more volume and 32% more external tube area than stock, rejecting more heat into the airstream when the engine is working hardest. Strutted tubes reinforce the core against the vibration and impacts that fatigue a low-mounted radiator, while removable stone guard shields the exposed face from debris. Aluminum, TIG-welded end tanks replace the failure-prone factory components, and a robust bracket design fits both the driver and passenger-side locations from a single part.----Direct fit for the 2015-2020 BMW F8X M3 and M4 - installs in the factory auxiliary radiator location with no cutting, fabricating, or adapter work required. Backed by the Mishimoto Lifetime Warranty.
Aluminum radiator engineered for efficient heat dissipation and optimal engine cooling. Precision-fit design ensures easy installation, corrosion resistance, and reliable performance across varied driving conditions.
- Built for back-to-back track sessions - the upgraded auxiliary radiator adds the cooling capacity the S55 needs to hold temperatures through sustained high-load driving, where the factory unit heat-soaks and gives up margin.
- Strutted tubes resist vibration and impact - internal tube reinforcement strengthens the core against the road vibration and debris strikes that fatigue a low-mounted radiator over time.
- 32% more external tube area for greater heat rejection - paired with a 9% larger core volume, the expanded core moves more heat into the airstream than the stock auxiliary radiator.
- Mounts on either side of the car - a robust bracket design fits both the driver- and passenger-side auxiliary radiator locations, so a single part covers either position.
- Confirmed direct fit for the 2015-2020 BMW F8X M3 and M4 - installs in the factory auxiliary radiator location with no cutting, fabricating, or adapter work required.
- No plastic tanks to crack - aluminum, TIG-welded end tanks replace the factory components that fail under repeated heat cycling and high-output use.
- Removable stone guard shields the core - protects the exposed face from road debris thrown up at the front of the car.
- Own it for life - backed by Mishimoto’s Lifetime Warranty, your investment is protected long after install day.
Fitment
2015 BMW M3 Base
2015 BMW M4 Base
2016 BMW M3 Base
2016 BMW M4 Base
2016 BMW M4 GTS
2017 BMW M3 Base
2017 BMW M4 Base
2018 BMW M3 Base
2018 BMW M4 Base
2019 BMW M2 Competition
2019 BMW M4 Base
2019 BMW M4 CS
2020 BMW M2 Competition
2020 BMW M2 CS
2020 BMW M4 Base
2020 BMW M4 CS
2021 BMW M2 Competition
|
| Air Freight Prohibited: false |
| Not Carb Approved: false |
| Carb Acknowledgement Required: false |
| Ltl Freight Required: false |
| Prop 65: Y |
| Part Type: automotive |
| Epa: N/A |
| Units Per Sku: 1 |
| Regular Stock: t |
REFUND POLICY
We have a 14-day return policy, which means you have 14 days after receiving your item to request a return.
Returns accepted for 14 days
Customer provides return shipping
20% restocking fee
No returns on final sale items
To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
To start a return, you can contact us at support@mo-moto.com. Please note that returns will need to be sent to the following address:
Mo-Moto/Returns
6082 W Seltice Way STE 121
Post Falls, ID 83854
If your return is accepted, we’ll send you a return shipping label, as well as instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.
You can always contact us for any return question at support@mo-moto.com.
Damages and issues
Please inspect your order upon reception and contact us immediately if the item is defective, damaged or if you receive the wrong item, so that we can evaluate the issue and make it right.
Exceptions / non-returnable items
Certain types of items cannot be returned, like perishable goods (such as food, flowers, or plants), custom products (such as special orders or personalized items), and personal care goods (such as beauty products). We also do not accept returns for hazardous materials, flammable liquids, or gases. Please get in touch if you have questions or concerns about your specific item.
Unfortunately, we cannot accept returns on sale items or gift cards.
Exchanges
The fastest way to ensure you get what you want is to return the item you have, and once the return is accepted, make a separate purchase for the new item.
European Union 14 day cooling off period
Notwithstanding the above, if the merchandise is being shipped into the European Union, you have the right to cancel or return your order within 14 days, for any reason and without a justification. As above, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
Refunds
We will notify you once we’ve received and inspected your return, and let you know if the refund was approved or not. If approved, you’ll be automatically refunded on your original payment method within 10 business days. Please remember it can take some time for your bank or credit card company to process and post the refund too.
If more than 15 business days have passed since we’ve approved your return, please contact us at support@mo-moto.com.
