I would just go and buy a low temp thermostat like 160 degres
Nope thats a bad idea on a FI truck. The ECM is calibrated for a temperature to run most efficeint and if that temp is not reached it may not go into "Closed Loop" where it uses the O2 sensor to make it's mixture adjustments. This could lead to poor perforamance AND failing emmissions. 210 degrees is still an exceptable temp. My Suburban specs a 195 degree thermostate and the AUX electric fan doesnt come on till 225! This is a truck with a 10,500lb tow capacity.
Put in the recomended temp thermostat. Toyota designed the ECM to work with that temp.
