I have a 170 degree thermostat installed and my dash still shows 210.

 

Your fans probably still turn on at 210

 

I'll have to check that. Just did a TS cam, DOD delete, milled heads .027", shorty headers and a black bear tune. They wanted to know the temp I thought that was for fan reasons.

 

170 stat doesnt mean the truck will camp at 170. Its still going to equilibrate to operating temp (190-200). All a 170 stat does is make it take longer because it starts letting the fluid cool sooner.

 

The thermostat is designed to maintain its set temp right? The only way it would go higher is of the water pump wasn't moving enough water or the radiator isn't big enough to cool or the electric fan isn't coming on early enough.

 

no

if you have a 10 degree stat, will the engine run 10 degrees?

Thermostats simply regulate the temperature of the coolant in the block. The entire system will eventually reach equilibrium with the operating point of a gasoline motor, 190-200 degrees. You will see a reduction in temp on the highway on cool days, but a colder stat only provides the benefit of giving the cooling system a jump start.

 

Whether you choose to believe it or not, here is an article for you. In this article they do say that best way to take advantage of the lower stat is to lower fan set points. But to my point, the system will not; now or ever; regardless of fan set points, stay at 170. She will now, and forever ride up to 190-200 when being driven. The only time you will see lower temps is on the highway, light load, lots of cooling. As for your "problem" I dont think there is anything wrong with what youre seeing. My Tahoe has a 185 in it, and its always at 190 +/- some when I log it, unless Im on the highway. So Im not 100% full of **** here or trying to be argumentative just because I want to argue on the internet. My fans come on at 195, and Ive seen as high as 213 on a long grade with a trailer. May have gotten hotter but I backed out and pulled over because trans was 196.

Low Temp Thermostats: What?s the Advantage? | Tuner University

 

The gauge is just a guess anyway. If you log a GMT-900 with say a scanner or HP Tuner the dash with show 210 when the coolant temp is at 180 degrees on the engine coolant temp sensor.

The dash will stay at 210 even though the coolant temp is 20-30 degrees cooler.

 

I was wondering if the dash is just a calculated # or something. It has never been above or below 210 when it's warmed up. Load or no load winter or summer.