The Mishimoto performance aluminum radiator for the Mazda RX-8 is the ideal upgrade to the stock RX8 radiator. Designed and specifically engineered to maximize cooling efficiency by up to 30%, boost engine functions and protect your car from overheating. Whether you use your Mazda RX-8 for daily driving or take it to the track, many people overlook the importance of installing an upgraded radiator in their engine. A stock radiator cannot handle the heat that comes along with having a great deal of horsepower. The Mishimoto Mazda RX-8 radiator features a lightweight dual core, 100% brazed aluminum, and polished end tanks. Every Mishimoto Performance Radiator is a direct OEM fit, making installation effortless, no cutting or modification is required.
- Direct fit for the 2004-2008 Mazda RX-8
- Overall Size: 26.4″ x 19.9″ x 2.07″ / Core Size: 14.17″ x 25.12″ / Rows: 2
- Inlet & Outlet: 1.4″ / Core Thickness: 1.57″ / Tank Wall Thickness: 0.08″
- TIG-welded aluminum radiator includes magnetic drain plug
- Mishimoto Lifetime Warranty

















welder314 –
Mishimoto claims that this is an exact OEM fit. It’s far from that. Let’s see… brackets that hold the fan were so far off I had to machine new ones. Primary mounting tabs on top are so small that you can’t even use a normal nut, much less the factory one. Not to mention they weren’t even spaced correctly. Again, more custom machined parts. The mounting bungs for the AC condensor were not even close to the right stand-off, so the condenser can’t even be mounted. So I had to machine out some delrin spacers. What should have been a quick install turned out to be a full day project… good thing I have a machine shop and a TIG welder.The box that they ship this in is amazing – it’s super-thick beautiful black cardboard, with a perfectly sized foam insert. If they put half the effort that they did into making the box into making the actual product, they would have a great product.The radiator itself is ok – nothing spectacular. If you look inside the fittings, you can see where they didnt even bother to trim excess material, and fitup is not that great on the inside. This will likely reduce overall water flow. Outside it looks great, of course.I would not recommend this if you’re just going for an OEM style radiator – just get a real Mazda one and save yourself the headache.
Jeremy Warnes –
Awesome radiator, only issue was having to oblong a mounting hole in the plastic fan shroud, keeps cool, holds more antifreeze.
Mike duffy –
BUYER BEWARE!!!!!!! i have never had so many fitment issues on a name brand radiator in my life, NOTHING fit the way it was supposed to. the only thing that kind of fit was the condenser mounts. the mounts at the top are impossible to line up or even get a bolt on to hold the radiator in place, the fan mounts were about 1/4 inch off to the right, since i couldn’t get the top mounts in, the bottom mounts were not aligned correctly. i REALLY think it needs to be redesigned OR have a higher QC process.
Derek –
Mazda rx8
Big~Hunk –
Performance 2 row all aluminum radiator it is. Direct fit…it is not…luckily I live close to work and was able to take my bike while working on the fitment issues. Mishimoto sent me a new one and same problem. They don’t know why but amazon issued a refund. Works great after 3 weeks of finding the time to modify it.
amanda williams –
I decided to give mishimoto a try over my usual koyo, and I’m not impressed.. Holes don’t align, you can’t even get the top two mounting nuts started because they welded the aluminum brackets too close to the end tank..I expected better, but this just reminds me of cheapo Chinese eBay stuff.. Can’t recommend!
Levente Sardi –
I ordered this item due to me living in Florida where temps are fairly or very high all around the year, so better cooling on an RX8 is a must. Alongside this product, I got the matching fans and fan shroud, and low temp thermostat, all from Mishimoto.As the caption suggests, and as others have mentioned before me, pretty serious fabrication is needed if you are wanting to fit these the same way as the OEM rad. The ports themselves are fine, although I opted to use different style hose-clamps instead of the OEM ones to make sure they seal properly. I used the Mishimoto fans with their respective bracket, which bolted on fine for the most part. I do not agree with the type of fasteners provided with the fans, but the shroud went on eventually. The rad mounts were a whole different animal… The top ones are welded so close to the body of the radiator that I could not get them to sit on the OEM rubber standoffs, let alone bolt them down. The bottom rad mounts were not even close to fitting, need completely custom ones to support the rad from underneath.Temperature-wise I will come back with feedback. Unfortunately, the thermostat I received appears to be faulty and stuck open at all times, so I will not be able to provide accurate feedback until that is resolved.TL;DR: Prepare to fight it at every step of the installation.
Rosayope –
The radiator itself look amazing the welds are beautiful and it’s shiny. That’s where the benefits end. The fans are louder and have less cfm than stock and aren’t staged. I previously had overheating problems with my stock radiator so I decided to “upgrade” instead my car now overheats faster than with stock fans and stock radiator. I live in Florida where in the summer it can get to 98 degrees and I can’t even use my a because it will put too much strain on the cooling system AT IDLE. I’m extremely disappointed with this product and have since gone with a different company’s radiator and now all my cooling problems are solved. I can’t believe a company with such a name can sell such a bad product.