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Built to order item. Lead times are typically 2-4 weeks before shipping.
Need a more accurate estimate? Call (636) 429-7020 and our team will be happy to help.

Mishimoto  |  SKU: MISMMRAD-CIV-12SI
9% off

Mishimoto 12-15 Honda Civic Si Performance Radiator

Sale price USD 40006 Regular price USD 44012

Can I pick up my order or have it installed at your shop?

Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at636-429-7020or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.

How do I know if this part fits my vehicle?

Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.

What if I need to return a product or it’s defective?

Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)

What's the lead time on custom or fabricated parts?

Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at636-429-7020and we’ll confirm current availability or estimated ship dates.

Description

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. All-aluminum construction with precision TIG-welded end tanks outlasts the factory plastic-tanked unit prone to cracking under heat cycling and repeated high-rpm use. A 63% increase in core volume over the OEM radiator delivers greater surface area and thermal capacity, keeping coolant temperatures stable during back-to-back pulls, spirited street sessions, and weekend track days where the stock radiator starts to fall behind.----Designed as a direct-fit replacement for the 2012-2015 Honda Civic Si, this radiator drops in without cutting, fabricating, or modifications, and works seamlessly with all stock hoses and components without alteration. The included high-pressure radiator cap maintains optimal system pressure from the first drive, extracting the full benefit of the upgraded core. The Mishimoto Magnetic Drain Plug catches ferrous metallic debris before it circulates through the cooling system, protecting your K-series engine internals and extending service life beyond what the factory setup allows.----Don't wait for your stock radiator to crack and leave you sidelined. Whether you daily drive your Civic Si, push it hard on weekend canyon runs, or are building toward a higher-output K-series setup, this aluminum radiator handles the sustained thermal demands your factory unit was never built for. Proactive cooling upgrades protect your engine investment - and this one is built to outlast it. Backed by the Mishimoto Lifetime Warranty, this Performance Aluminum Radiator is the last cooling upgrade your 2012-2015 Honda Civic Si will ever need.

This Part Fits:

Year Make Model Submodel
2012-2015 Honda Civic Si