Thermostat Temp???

[mcboy]

Have a new to me 1996 Tahoe with 100k miles. Temp guage goes up to a Max of about 165F.

Going to flush and refil the cooling system and add a tranny cooler. There is a stock in radiator oil and tranny cooler in place.

Is there any benefit or drawback to using a lower temperature thermostat. Stock one is supposed to be a 195F

 

[punisher]

Too low a thermostat temp will accelerate engine wear, possibly delay closed loop operation and set a code in OBDII systems.

 

[mechtech]

Put the stock 195 in.
When you need it under load, either one will be open, anyway.
Your engine will be more efficient for normal driving [less heat loss from combustion to the head - trying to maintain homostasis].
Parts will be full expanded to seal better.
There will be less condensation in the oil, and less acids.
Your coolant temp sensor readings control mixture and timing. You will never fully warm up, as the computer sees it, and will be running richer than normal.
If there are any winter conditions, your heater defroster will work much better.

 

[Shaman]

It is possible, don't know about your Tahoe, but some other GM's had PCM codes set to only pick up knock after 163 Degrees. That right there alone is enough reason for me to go at least 180, or 195 if you are stock or close to stock.