Originally Posted by aim4squirrels

3* colder? I better go get a jacket, brrr...

Originally Posted by HeyYou

After the engine has been running a while, thus, getting ALL the coolant nice and toasty, there is a real possibility that the system reaches 'steady state' and the thermostat just stays partially open. Depends on outside temp..... on the REALLY hot days, yeah, I could see that, but, below about 80 or so, I would suspect that it does indeed cycle.

Originally Posted by jamesnb

In the summer, I doubt your truck will run much cooler even if you take the thermostat out of the system completely. The only way to get it to run cooler is to get a bigger radiator.
Ethanol does make the engine run cooler and burn more fuel.
Regarding the ac kicking out going up hills-- I think what he means is the air blowing out of the vents cuts out. There are two vacuum check valves in the line coming off the manifold. Find that vacuum line and check for leaks. If you don't have a vacuum gauge, I'd just replace the vacuum hose and check valves (they're cheap). Make sure the vacuum line off the manifold isn't clogged with oil sludge.
Also, check if your plenum gasket is blown. Do you get a lot of valve clatter when the air cuts out?

Originally Posted by Augiedoggy

my guage was always around 205-210 before my 180 state now its between 185-195 and never goes ove 200 degrees...the stat determines and regulates the engines normal operating temp....the radiator is designed to be able to maintain that but there is some tolerance where it can usually keep things cooler than what it was finally speced at... my vette will run at 170-175 all day on the thruway with its 160 state....berfore it was always closer to 215-220 (think the stat or my temp gauge is off a bit on both vehicles) now if I could only keep my air cooled vw from overheating....

Originally Posted by charlie1935

You need a new radiator cap for the air cooled VW.