vs
Thermostat MISHIMOTO or AISIN
Hard to say if it’s directly OE to Subaru, but I use Aisin thermostats and water pumps on every Subaru engine I do, they function the exact same and are equally as reliable as the original equipment, not to mention these thermostats are $15 on amazon compared to $40 from Subaru.
Pros: equally reliable, functions same as OE
It’s now got an 85°c Mishimoto thermostat. Took it out today and got it up to temp and did multiple 0-85mph pulls. The new thermostat opens at 85°C/185°F. Under load the coolant never registered above 197°F!!!!
Pros: coolant stable, low temperature
Vehicle:
Volvo XC70
Mishimoto has a great thermostat plus it has a lifetime warranty
Pros: great thermostat, lifetime warranty
I spent a good chunk of change on the Mishimoto thermostat and it got stuck closed within a couple months. Needed the car back right away and all I could get was a dirt cheap MotorRad one. Darn thing has been it in now without issue for a good long while now.
Pros: working without issue
Cons: stuck closed quickly
New thermostat (Aisin brand), fresh oil, fresh coolant, replaced at that time. Coolant system bled well. No leaks. Heat worked flawlessly. AC worked after the swap. Overheated the drive home after that swap, turns out the radiator fan module got fried on the final drive (it was above 250 on coolant temps before replacing the engine, on a 30 minute, fast, highway drive). Ordered a new one. Everything working perfect now at the right temperature points. Engine times reading perfect too (watching live data). On a 30 minute highway drive tonight, returning home after the same drive 2 days ago with zero issues, it overheats again. Radiator fans are working. The one thing I changed during the drive was turning down the heat from HIGH to 75. No more than 10 minutes later I hear the bubbling in the heater core area. Take my exit from the highway, and the red temp light starts flashing, temps read 239, and the bubbling worsened. Temps stayed above 228 until I made it home from my exit. Worse at red lights. Turned off for 10 minutes, turned back on, temps went up to 232 at idle, holding steady. Lower radiator hose read 102 degrees, upper hose reads 190.
Pros: heat worked flawlessly, AC worked
Cons: overheated, bubbling in heater core
Vehicle:
Subaru Outback
Get that mishimoto garbage out of there and put a new oem thermostat in there. Unless you really lile pulling the engine out, to replace coolant seals and rusted rotors...
Cons: poor quality, causes damage
please remove the mishimoto thermostat they fail a lot, it happened to me as well.
Cons: frequent failures
Même souci sur 350Z
Le thermostat Mishimoto s'ouvre à 82° au lieu de 68°/ la réponse du constructeur → du moment ou la température reste stable !!!!!!!!!
Je suis énormément déçu de cette réponse surtout au prix et frais de douanes que cela comporte.
Cons: s'ouvre à mauvaise température, déçu de la réponse, frais de douanes
Vehicle:
Nissan
Aisin THF-003 thermostat was used (I believe this is what I'm regretting). It's like the thermostat isn't opening? Everything else seems fine - it's clearly getting hot. Little to no heat at idle. No circulation = overheating of the engine. Is the replacement thermostat stuck shut?
Cons: thermostat not opening, overheating engine, little to no heat
Vehicle:
Subaru Impreza
Part number: THF-003
Forget about the Mishimoto thermostat. The OEM thermostat is way more reliable and does the job.
Cons: less reliable than OEM
Vehicle:
Mazda
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Which thermostat to choose — MISHIMOTO or AISIN?
If choosing thermostat across many manufacturers, check the part ranking. If your choice is down to two brands, the PartReview part comparisons help.
We compare thermostat across these categories:
- PR Score.
- Overall ranking.
- Vote balance.
- Average rating.
- Number of reviews.
- Feature ratings.
- Car owners’ choice.
Which thermostat are better — AISIN or MISHIMOTO?
In March 2026 on PartReview, thermostat AISIN were overall better than MISHIMOTO.
- MISHIMOTO received a PR Score of 32 out of 100, and AISIN scored 83 points.
- MISHIMOTO ranked 14 in the overall ranking, and AISIN ranked 5.
- The average rating is higher for AISIN (4.3) than for MISHIMOTO (2.2).
-
Thermostat AISIN have better feature ratings than MISHIMOTO:
- Overheating - owners believe, that this property for AISIN is better than MISHIMOTO.
- Slow warm-up - drivers claim, that this property for AISIN is outperforms MISHIMOTO.
- Cabin heat - reviews suggest, that this property for AISIN is preferred to MISHIMOTO.
Which thermostat are more popular — MISHIMOTO or AISIN?
Thermostat MISHIMOTO and AISIN were equally popular according to data in March 2026.
By vote balance, thermostat AISIN surpassed MISHIMOTO:
- For MISHIMOTO, the ratio of positive (16) to negative (34) votes is -18 votes.
- For AISIN, the ratio of positive (26) to negative (5) votes is 21 vote.
By number of reviews, thermostat MISHIMOTO surpassed AISIN:
- For thermostat MISHIMOTO there are 16 reviews: 4 positive, 2 neutral, 10 negative.
- For thermostat AISIN there are 10 reviews: 8 positive, 1 neutral, 1 negative.
Which thermostat do car owners prefer — MISHIMOTO or AISIN?
In March 2026, according to PartReview, thermostat MISHIMOTO and AISIN have not taken top places in car-specific ratings. You can help by adding your review about these manufacturers.
Other comparisons of thermostat
If this comparison didn’t fully answer your question, there are many others on PartReview.
For example, comparisons of thermostat MISHIMOTO with: MotoRad, Wahler, OEM Volkswagen, Mahle, OEM Mazda, MOPAR, Gates, OEM BMW, OEM Nissan, OEM Audi.
Also available: comparisons of thermostat AISIN with: MotoRad, Wahler, OEM Volkswagen, Mahle, OEM Mazda, MOPAR, Gates, OEM BMW, OEM Nissan, OEM Audi.
You can also see who is better among other thermostat manufacturers: Wahler or MotoRad, OEM Volkswagen or MotoRad, Mahle or MotoRad, OEM Mazda or MotoRad, MOPAR or MotoRad.