Important!: Lower thermostat, really needed?

JennaBear

Member
Mar 29, 2012
514
1
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A common belief is that a cooler running engine will reduce intake air temperature. The reality is that outside of idle, there is very little heat transferred from the engine to the intake charge. The mass of air moving across the incredibly small surface area of the intake ports is too large and too fast to allow for any large temperature transferance.


As a vehicle sits out overnight, you may notice condensation on the windows, hood, etc from moisture in the air. That same moisture ends up in the crank case as well. An engine that does not reach the manufacturers operating temperature will not as easily boil off that condensation, especially if only short trips are taken.


Here is some info to further whet your palate: http://www.tuneruniversity.com/blog/2012/04/low-temp-thermostats-whats-the-advantage/


With a 160* thermostat, the average operating temperature of a GM engine is approximately 180*. With the OEM thermostat, it is around 199*. A few minutes on the dyno can quickly show temps above 210-220*, regardless of the thermostat. As long as intake air temperatures remain static, power output is static and sometimes even BETTER under the 210-220* range.


In short, keep your stock tstat.
 

Colyn.

Acrophobic
Mar 17, 2012
2,223
6
38
Alma, GA
Thats what ive always heard, is to not change the thermo in our trucks because operating temp is what it needs to be... and when racing its going to get hot regardless so your only making it hard on the engine at start up and normal conditions


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Charlie

Member
Mar 21, 2012
784
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There are some exceptions, though. My 8.1 for example was going through about a qt every 1k miles. No smoke, no leaks, nothing wrong with the pcv valve... Some research turned up a theory of too much heat in the bottom end causing oil to vaporize. I installed a 180* thermostat and it cut down oil consumption to almost none. I agree though, 210-220* is the sweet spot.
 

JennaBear

Member
Mar 29, 2012
514
1
18
Yes, that would be an exception, however, that would be more inline with a design issue. The 8.1L benefits from a lower thermostat because oil gets too hot on the OEM thermostats. That an the 2500HD 6.0L tracks that see heavy towing use, we would suggest a 180*, but for that pupose only.