Davin 75

I recently noticed 5 Star is sell 170 degree thermostats for the 3.5eco . I am currently on the 93 performance tune and was wondering if anyone is using one yet or has any feedback on if it is a worthy upgrade. I personally am not sure if the cooling system in the truck could actually keep the temps that low.

Thoughts?

w00t692

https://www.rockauto.com/en/catalog/...hermostat,2200

Get that 180F one there. Best balance of fuel economy and cooling off the cylinder heads and turbos and the like.

Also the answer is yes, the cooling system will keep it around 170 when it's cooler outside and 180 when it's hot. Tells me that a 180 thermostat is probably the best bet.

BadCon

The 170 degree rating is when the thermostat starts to open, and there is usually a 20 degree spread from when it starts to open to when it is fully open. I have the 170 in my supercharged 5.0, and it keeps the truck between 185 and 190 degrees on a warmer day, and closer to 180 on a cool day. My cooling fans hit 100% by 188 degrees, so the truck does not get too much hotter then that at low loads. At WOT it'll keep rising until I let off, hitting about 200 at the end of the 1/4th and higher if I'm doing a longer pull.

For a mostly stock truck with a tune the 170 degree is not really necessary, and as another poster mentioned the 180 degree is a good compromise.

w00t692

^^ what he said, thermostats listed temperature are when they start to open not when they're fully open. My 170, though, my cooling fans don't even turn on. I have them set to come on at 180 something and they don't ever even turn on.

white15lariat

MPT said to run a 170, so I do.