I know someone who uses a 195 F thermostat in the winter but then replaces it with a 180 F thermostat in the summer, and he is convinced this is the way to go. This is what i have been doing as well, but then i have heard others say just leaver the 195 F in all year round, no benefit in changing it. I can't really say that the 180 makes the engine run any cooler in the summer anyway, it always seems to be in the 200 - 210 range unless it is really hot and i am driving up hill into the sun, then it gets more like 215 or even 220 and i get nervous and back off the throttle as much as i can.
Does anyone else actually put a different one in for warm weather than the one they use in winter?
thanks,
Paul

nope I dont change mine at all and I have no idea what one is in it.

180 all year around ,good heat in winter and 180 - 190 summer with my trailer and stuff on mountains area:chevy:

195 all year. It is way too much trouble to change it twice a year for the 15 degree difference.

never changed mine. but our weather is mild compared to most parts of this country