Thermostat question

[LAGA]

Once a vehicle has reached normal operating temperture, lets say 195F as in my 2001 Dodge Ram with a 5.9. Does the thermostat stay open all the time or does it continue to open and close ? In my case the cooling system is in perfect condition. I have read of benifits of going to a lower temperture of 180F but would not the lower thermostat stay open all the time ?

 

[ATS-V]

It opens and closes.

Generally reducing coolant temp drops engine effienecy.

 

[Rhymingmechanic]

The thermostat does not work like an on/off switch, as I understand it. I installed a 180F stat in my Chevy pickup, and the instruction sheet said it begins to open at 180F and is fully open at 200F. Specs for the cooler model were 160F and 175F.

I think a lot of people assume the thermostat will make engines run at the rated temperature, when the rating is actually the minimum temp. Max or normal temp has more to do with the rest of the cooling system.