MISHIMOTO 2008-2021 Subaru WRX / STI Coolant Overflow Tank

The Mishimoto Coolant Overflow Tank for the 2008+ Subaru WRX and STI replaces the factory plastic reservoir with a durable, TIG‑welded aluminum unit engineered for long‑term reliability. OEM plastic tanks are prone to cracking and discoloration from repeated thermal cycling, and their appearance detracts from the engine bay. Mishimoto’s aluminum construction eliminates these concerns, providing improved resilience and a refined aesthetic.

A CNC‑machined dipstick is integrated for quick and accurate coolant‑level checks, and the tank is designed to fit cleanly with both stock and Mishimoto WRX/STI radiators. Available in polished or anodized‑black finishes, the tank complements a wide range of engine‑bay styles while delivering a functional upgrade over the factory component. As with all Mishimoto WRX/STI products, the Coolant Overflow Tank is backed by the Mishimoto Lifetime Warranty.