Living in Michigan I get to see what these stats will commonly run in cold enough weather to cool them to as low as the thermostat will allow. The 160º stat's in an 04' and newer will run around 172º, the 180º stat's will run around 188º, and the stock will run between 194º and 198º fairly consistantly. These are temps from HPT logs in cold weather running. (under 60º outside temps)

For some reason the 03' and older trucks tend to be inconsistant at what temps they will run. I've seen 164º-184º with 160º stats.

I've bought them from many sources, most are just a re-boxed Moto-Rad. The best source I've found for 04' and newer is LPE.

 

I was driving my truck yesterday, everything seemed good, got off the freeway and went through a few lights, sitting at the last light before i was gonna get to my house and it back up to 200 or so, or at least that's what the guage on my truck was telling me.

 

I checked mine several times and when it would read almost 210 it was actually reading about 190-192 degrees.

 

160 stat at 180ish all the time.

 

I'm gonna check my coolant level again, but it seems like it still has air in the system, it never fluctuates like that.

 

Put my 160 in today, seems to like to run at 172-174. I let it idle for 20min after it was warmed up and it only hit 186... Now I am trying to decide what temp to have my fans turn on at.. currently they are still set for the stock stat. I am thinking like 184 on and 179 off or something like that.

 

When my truck idles it doesn't get too hot. But when i am runnin around town ECT gets right back to stock, around 195 or so, i get on the freeway, 175-180. I think the the cooling system just can't cool it at the thermostat setting. Oh well, just have to get a better radiator when i supercharge.

 

Ok after some more driving today here is what I found. Start and stop driving resulted in around 180-183. Highway seemed to settle in around 178 or so. What are you guys setting your fans at?

 

Might have had a little air in the system yesterday still, todays highway resulted in 174-175 temps

 

I still don't understand why people think that just getting a lower temp thermostat will lower the running temp of the engine. Simple physics and common sense tells us otherwise. You must lower the temperature settings of the fans to get any benefit from a lower thermostat. I think this is what this thread is saying, I'm glad at least a few people finally understand...