What type of thermostats are there?

[httrdd]

What is the best thermostat for higher performance engines. I would go right to oem, but I want to be sure I get the best one that can perform the way I want it to. I remeber my Trans Am guys used to put different temp stats in their cars for better flow so the engine runs cooler. Thanks. TJ

[Huffer]

This is an alternative to the Subaru OEM thermostat... read the link and the info, it shows why it's different to the stock one.

Basically, it opens at a lower temp setting to keep the coolant flowing...
https://www.grimmspeed.com/catalog/prod ... cts_id=162 (https://www.grimmspeed.com/catalog/product_info.php?cPath=91&products_id=162)

[nipper]

Grimm speed looks fine. The only two choices are Grimm and Oe really. Aftermarket does not have the jiggle vlave and usually has a smaller opening which forces the engine to run hotter. I think Grimm 160 is too cool for most applications. The ECU doesnt switch from open loop to closed loop at either 158 or 168 (i used to know that number) and 160 is just cutting it too close.

[httrdd]

Thanks for the info, but after calling around I bought the OEM that runs 170*. Not too many out there for our cars.