zer099

iTrader: (2)

Was not to sure where to put this but wanted to share the information. Part #21200-4W000 is a OEM thermostat that opens 10°F sooner then the stock thermostat. I confirmed this by dropping the massive $18 for one of these thermostats and testing it in some 170°F water. Turns out it does indeed start to open around 170° and was fully open by 175°F.

10°F might not be much to many but to some it's just enough and also gives extra option for thermostats for us as the Mishimoto (begins to open at 155°F) has apparently been universally hated by the 370z community for being a not so great product in the reliability department.

And yes: this is a direct bolt on/swap. I did a few searches and couldn't find the part number on the forum so this is mainly for future searches.

RMB5190

iTrader: (2)

Great find and appreciate the info hunting. Anything that helps keep these VQs cool helps.

Waste86

I believe this is the one that came on the 2008? As I believe I read somewhere that the 2008s had thermostats that opened earlier than later models.

zer099

iTrader: (2)

No worries.

And yes, It was in the 2008 coupes and used on a few other engines including most all VQs in the middle east market.

JSolo

iTrader: (14)

I thought the stock one was 195°F? Probably hotter temp for emission purposes. Wonder what other negative side effects might result with running a cooler thermostat?

zer099

iTrader: (2)

Stock is 180°F (according to the FSM). You see full open around 185°F which will give you about 190ish°F temps most the time on hot days and long drives. Last week I got up to 203°F just on the commute home. When I swap out mine I will do a test on the stock thermostat.

Baadnewsburr

iTrader: (3)

this is very helpful info...the 10 Degree drop may just make it a more liveable thermostat year round and be helpful in the summer...that 155 degree Mishimo sounds problematic especially if you leave it in in the winter and aren't tracking the car.