Subaru Genuine Thermostat & Gasket Kit 21200AA072 21236AA010

Good OEM thermo. Apparently the aftermarket ones are failing constantly (advice from my tuner for my 500hp STI)

Works great

BUY THIS. For years I had used those aftermarket ones. Because I have a needle indicator in my dashboard, I didn't know that my car RAN HOT for years. Slowly damaging electronics, seals and sensors. Like the head gasket, coil pack and wires. I used LIVE DATA on my OBD2 reader, and it showed between 180 and 224 for years. I read "experts" who said this was normal. Forester: Installed THIS THERMOSTAT. Car runs at 192 to 203. That's it. Now my car runs better, smoother, I don't leak oil (because seals don't expand), better compression - power up hills. Even without a functioning catalytic converter. Worth the millions of dollars you will absolutely spend on avoidable repairs and time and headaches firing the parts cannon at your travel machine.

For your sti there is nothing better for cooling than oem… this was great and good value

It has been months now, and no complaints. Works as it should, and it gives me peace of mind. Temperature remains right in the middle , and it never moves. Perfect OEM replacement. Previously, I used a non-OEM replacement, as advised from an independent shop, and it only lasted a few weeks. this is the thermostat you need for longevity and peace of mind.