PRODUCT DETAILS
Mishimoto Coolant Tank - FK8/FL5 Type R
For your FK8 or FL5 Civic Type R, the stock plastic coolant tank works…until it doesn’t. Heat, pressure, and age don’t do plastic any favors, which is why a lot of owners swap to an aluminum coolant tank FK8 / aluminum expansion tank Civic setup before it becomes a problem.
This Mishimoto Type R coolant tank is a direct-fit aluminum expansion tank for 2017+ FK8 and 2023+ FL5 Civic Type R. It replaces the factory Civic Type R coolant reservoir with a fully-welded aluminum body that won’t puff, fade, or crack after a few hard seasons. It’s a legit Civic Type R coolant upgrade, not just an engine-bay dress-up piece—though it definitely cleans things up under the hood.
You can grab it in two finishes:
- Mishimoto Civic tank black (SKU: MIS-CTR-17EMWBK) – subtle micro-wrinkle that looks OEM-plus
- Civic Type R tank Rallye Red (SKU: MIS-CTR-17EMWRD) – matches the car’s red accents and actually looks like it belongs there
Either way, you’re getting a Type R aluminum expansion tank that bolts in where the stock one lives on both FK8 Civic expansion tank and FL5 Civic expansion tank applications.
This Mishimoto Civic Type R tank doesn’t just sit there looking pretty. Internal baffling keeps coolant from sloshing away from the outlet during hard braking, long sweepers, or curb-hopping on track days. That matters because when the coolant pulls away from the overflow port, your system can ingest air. Air means hotspots, inconsistent temps, and eventually headaches. The baffling in this Mishimoto expansion tank FK8 / aluminum expansion tank FL5 keeps the pickup covered in fluid so the system stays burped and happy even when you’re abusing it.
There’s also a built-in sight glass, which sounds minor until you’ve tried to check coolant level in a hot, stained plastic tank. Here you just glance at the window—no more guessing if the level mark is actually where the coolant is or just where Honda molded the plastic.
Up top, Mishimoto includes a 19 PSI filler cap that locks down pressure for more consistent boiling margins on track. If you’d rather keep things closer to stock behavior, you can still run your OEM cap on this Mishimoto coolant tank Civic setup—no weird adapters or hacks.
We run this exact Mishimoto Type R coolant tank on our own cars because it solves a real weak point and cleans up the bay at the same time. And if you’re worried about longevity, Mishimoto backs it with their Lifetime Warranty, so you’re covered as long as your FK8 or FL5 is around.