If the thermostat doesn't open until it reaches the target temperature, why does a 160 stat warm slower than a 180 stat?
Shouldn't they both reach 160 degrees at the same time?

 

yes they do. since in either case the thermostat would be closed until the opening point. it's all in your head.

 

Maybe I misunderstood your question but isn't the answer pretty obvious?

If the thermostat opens at 160° instead of 180°, coolant is going to be reaching the engine earlier and thus it's going to take longer for the engine to come up to OT (since the coolant begins taking heat away from the engine at 160° instead of 180°).

 

he was just asking if they both would reach 160 at the same time, which they would. the only difference is that the engine would continue up to 180 with the higher stat and not stop at 160.

 

That is what I'm trying to figure out. If a car owner decides his optimum operating temperature is 160, why is a 160 stat too cold for the winter? I've heard extreme cases of people changing stats each season and I'm trying to figure out why. Wouldn't the engine run at 160 no matter what the outside temp is? (assuming sufficient cooling capacity, that is) If 160 is good for the summer, it should be good for the winter, no?

 

Air charge over the radiator. Take the much colder air that comes with winter and pass that over the radiator. It cools down the fluid in the radiator MUCH faster per cfm of air. So the engine runs at 160, stat set. Obviosly you know how coolant is returned to the radiator to disperse of heat and how the cooled coolant is then drawn back into the engine. Say 160° coolant returns to the radiator. It's job has no definition of how far temperature wise to cool. It just cools. So now, lets say the temp drops 30°, and then returns to the engine. In itself, there's nothing wrong with that. Enter the CTS. The CTS takes that new 130° and thinks the engine is colder than what it really is and dumps more fuel than what is really needed. Now you are running rich.

And I don't know about you, but the hotter the coolant in the intake, the better my heater works. And I like my heater.