MISHIMOTO Honda Civic Type-R Thermostat 17-21

The Mishimoto Racing Thermostat for the 2017+ Honda Civic Type R is engineered to improve cooling efficiency and stabilize operating temperatures under both daily and high‑performance driving. The K20C1 engine generates significant heat, and the factory thermostat delays coolant circulation, allowing temperatures to rise quickly. Mishimoto addresses this by lowering the thermostat’s activation point, enabling coolant to enter the radiator sooner and begin shedding heat earlier in the cycle.

This racing thermostat begins to open at 68°C (154.4°F), which is 10°C earlier than the OEM unit, and reaches full opening at 83°C (181.4°F), 7°C earlier than stock. The result is improved thermal control, reduced heat‑soak, and more consistent performance during track sessions, spirited driving, or high‑ambient‑temperature conditions.

Pairing this thermostat with the Mishimoto Performance Aluminum Radiator and Direct‑Fit Oil Cooler Kit provides a comprehensive cooling solution for the FK8 and FL5 platforms. As with all Mishimoto components, the Racing Thermostat is backed by the Mishimoto Lifetime Warranty.

VEHICLE FITMENT

Honda Civic Type R Model years 2017+ Direct fit for K20C1 cooling system

MODELS

Civic Type R FK8 (2017–2021)

Civic Type R FL5 (2023+)