Mishimoto MMTS-CIV-06 Racing Thermostat for 06-13 Honda Civic Si K20/K24

Vehicle Fitment

• 2006-2013 Honda Civic Si (K20Z3 & K24Z7 engines)
• Also fits select 2004-2008 Acura TSX (2.4 L) and 2007-2013 Honda CR-V (2.4 L)
• Fitment confirmed through 2025. Coverage beyond 2025 unconfirmed at time of listing.

Features

• Performance racing thermostat calibrated to open at lower temperatures
• Direct-fit replacement for thermostats on applicable Honda/Acura platforms
• Promotes greater engine coolant flow earlier for improved heat management
• Helps maintain cooler engine operating temperatures under load
• Beneficial for street, track, and modified applications seeking thermal efficiency
• Constructed to OEM-replacement standards for reliable performance
• Includes high-quality O-ring gasket for secure seal
• Backed by Mishimoto Limited Lifetime Warranty

Specifications

• Part type: Racing engine coolant thermostat
• Activation temperature: ~154.4 °F (68 °C)
• OEM activation temperature: ~172.4 °F (78 °C)
• Compatible engines: Honda/Acura K-series (K20/K24)
• Construction: Direct-fit metal thermostat body

Included Components

• 1x Mishimoto MMTS-CIV-06 racing thermostat
• 1x High-quality rubber O-ring gasket
• Installation instructions

Product Description

The Mishimoto MMTS-CIV-06 Racing Thermostat is engineered as a direct-replacement engine coolant thermostat for 2006-2013 Honda Civic Si models equipped with K20 or K24 engines. Calibrated to open at approximately ~154.4 °F (68 °C), which is lower than typical OEM thermostats (~172.4 °F), this performance thermostat allows coolant to begin circulating through the engine and radiator sooner - helping reduce peak coolant temperatures under high load or spirited driving conditions.

In addition to Civic Si fitment, this thermostat also fits select 2004-2008 Acura TSX and 2007-2013 Honda CR-V applications with compatible engines. Built to OEM-replacement tolerances and backed by the Mishimoto Limited Lifetime Warranty, the MMTS-CIV-06 supports improved thermal performance for street, track, and modified vehicles while maintaining proper warm-up behavior and reliable operation.