Mishimoto 2012-2015 Honda Civic Si Performance Radiator

This Mishimoto performance aluminum radiator is a direct-fit upgrade for 2012-2015 Honda applications covering Civic Si. It replaces the weak points of the stock part with stronger materials and better flow or cooling so heat, boost and abuse stay under control on street and track duty. AutoTalent lists verified US-market fitment in the table below.

Why upgrade

Upgrade the cooling system of your 2012-2015 Honda Civic Si with this Mishimoto Performance Aluminum Radiator, built to manage the sustained thermal output of a high-revving K-series engine on the street and the track. These kits are engineered around real chassis packaging, so hoses, coolers and adapters line up without fabrication on the listed years. Follow the published torque specs and install guide, reuse sensors where instructed, and confirm clearances if you run other supporting mods. Every unit ships with the Mishimoto Lifetime Warranty for as long as you own it.

Features

• Built for the high-rev demands of the Civic Si K-series — the oversized aluminum core absorbs sustained thermal output during back-to-back pulls, spirited street driving, and track sessions where the stock radiator begins to fall behind.
• 63% more core volume over stock — the enlarged core delivers greater surface area and thermal capacity than the factory unit, running measurably cooler when the K-series is pushed hardest.
• All-aluminum construction, no plastic to crack — full aluminum end tanks joined by precision TIG-welds replace the factory components that fail under heat cycling and sustained high-rpm use.
• Magnetic drain plug removes ferrous debris before it circulates — catches metallic particles from the cooling system to protect K-series engine internals and extend service life beyond the stock interval.
• Included high-pressure radiator cap maintains optimal system pressure — delivers enhanced cooling performance from the first drive without sourcing additional components.
• Drops in without modification — confirmed direct fit for the 2012-2015 Honda Civic Si, compatible with all stock hoses and components — no cutting, fabricating, or adapter work required.
• Own it for life — backed by Mishimoto's Lifetime Warranty, your investment is protected long after install day.

What's Included

• Mishimoto Radiator
• Mishimoto Radiator Cap
• Magnetic Drain Plug
• Mishimoto Lifetime Warranty

Specifications

Fitment Notes

Verified against Mishimoto US applications and dealer listing for 2012-2015 (1 rows). Years extended to 2027 where the US model remains in production.

Vehicle Fitment