Put a koyo rad in it and it’s been good to go.
Pros: good to go
Reviews of Koyo parts For Business
Average Rating
?
The manufacturer's average rating is calculated based on ratings of all its spare parts. It determines the place in the manufacturer ranking
4.4
Manufacturer Ranking
#23
57
Spare Parts
1
Country
Japan
Website
koyo.eu
Spare Parts
Comparisons
If you go aluminum Koyo is the way to go.
Pros: good aluminum radiator
I went with Koyo. CARid was the best price at the time. Been 7 years and no issues.
Pros: no issues for years
Radiators aren\u2019t supposed to leak. I have the same Koyo radiator in my NA Z, just put it in this past summer. I def do not have that leak.
Cons: radiator shouldn't leak
Vehicle:
Nissan
Personally I’d be buying a koyo in full aluminum.
Pros: full aluminum
I went with a Koyo radiator, which is considerably better built than the factory piece, cost less than $300 with new hoses, and took maybe 2 hours, start to finish. Of course, I replaced the coolant at the same time.
Pros: better built than factory
Vehicle:
Honda S2000
just tested my new koyo hyper V at the track and that thing kept it rock solid cold, 180-203f the entire day but it was like 68 degrees out lol.
Pros: kept it rock solid cold
Koyo for top quality, mishimoto for normal quality. Both will do the job well
Pros: top quality
Cons: price higher than Mishimoto
Mine developed a small slow leak out of that nub two weeks after I bought it. Koyo gave me the run around on their warranty, insisting on photos of a destroyed radiator for replacement. I gave up. It’s a shame because it fit awesome and looked great.
Pros: awesome fit, great look
Cons: developed slow leak, poor warranty service
Vehicle:
Honda S2000
The problem I'm running in to is that the upper hose connection is positioned differently on the Koyo N-Flow/dual pass(RH020539N) and it's really close to the Q45 throttle body and attached TPS. I've already cut off the unused socket on the TPS which gives me more room but still not a ton to work with.
Cons: tight hose connection, poor fitment
Vehicle:
Nissan
Part number: RH020539N
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Owner reviews of Koyo products
The Koyo brand is registered in Japan. Official website: http://www.koyo.eu/ .
In March 2026, PartReview recorded 57 reviews across 1 part by Koyo. Average rating — 4.4 out of 5.
Koyo is in the PartReview manufacturers ranking, currently at position 23. Over the last 30 days it dropped by 0 points.
Popular Koyo parts
The most popular Koyo products on PartReview:
- Engine radiator Koyo - 57 reviews. PR Score — 92, average rating — 4.4.
Most owner reviews about Koyo parts are collected on these pages.
Top-rated Koyo parts
Koyo achieved top positions in these PartReview part rankings:
- Best engine radiator — ranked 1 among 9 manufacturers. Received 1069 votes.
Comparisons of Koyo parts
The most interesting comparisons of Koyo with other manufacturers help you see which is better: