I doubt your gas mileage will increase much with a good thermostat. Let us know.
My car's was stuck open just enough to keep it running cool if not cold. I replaced the thermostat. So now it runs at the proper temperature but fuel consumption is about the same.

Really?!? I would have thought it was a fanstat.

 

The thermostat is not what "tells" the fan to turn on. That would be the fan switch.

 

Does anybody have a diagram or picture showing where the fan switch is? Also, how much would it be to replace it?

 

whatever, it's first in line you fucks

 

hey bro i have a 91 ls and i just ran a switch to the battery and bypassed the fan relay so i hit a switch and BOOM instant fans...but yea bro if u do that reaplace ur thermostat anyways...