Engine radiator MISHIMOTO or KOYORAD

I usually Autox and track my rx8. My last event it was 90 outside and after fueling and a run my temp was only 205. I do have an aluminum misimoto radiator

Koyorad. Their fit and finish is OEM level.

One of the best replacement radiators for sure but you’ll have to get an external transmission cooler for it to work as the Koyorad doesn’t have an integrated transmission cooler that autos use.

Replaced it with that exact same Mishimoto rad and have had zero issues with the fitment or durability for 10+ years and 60k miles later. I believe I saved ~$600 or so by not pursuing OEM replacement.

I got the mishi rad and racing thermo in mine for vegas. Love it, no issues thus far after 2 years.

i went with a Koyorad SKU: 910-371 for my NB from Moss. I live in hot sunny florida, and took it to the track a few times. never an issue. i just drove it hard to the hardware store.

Later I came across a deal for a Mishimoto radiator and had that installed. I’ve had no issues with my Mishimoto, and I bought it before seeing most recommending the Koyo Radiator over Mishimoto.

I put a Mishimoto rad in the R53 on the same terms as you @whalemingo - and only learned of Mishi's QC decline after I put it in the car. So far, it's been just fine.

stay away from mishimoto, their radiator quality is sub par

The Mishimoto all aluminum radiator (2 core) started leaking this past January (86k miles) in the top left corner (if you are facing the grill). From what I can tell with reviews, I was lucky to get 18k miles on that radiator.