I have been running under the assumption that my car had a 180* thermostat put in by the previous owner, as evidenced by the fact that on the highway I never saw a temperature above 188* unless I was really pushing the engine, and on cold mornings I could turn on the heat and never go above 184*. So I have been contemplating putting a 195 in because that is stock and would give me the best mpg. I had been weighing the pros and cons, having to re-bleed the system and all that. This was the first time I would be opening the cooling system, so bleeding was new to me.
I bit the bullet and went for it, picked up a 195 and a rubber gasket/seal, and a jug of the green stuff. I unbolted the housing and pulled out the old and put in the new, only lost about a cup of coolant, so I opened the bleeder screw, topped off the radiator, and closed the bleeder once it started peeing coolant. I let it warm up and watched the gauge
gp04cluster.jpg(this is an old pic, not from today), she climbed to just under the 203 line sat for a minute and fell back to just over the 194 line.
After this whole operation I picked up the old thermostat, what did I see stamped into the bottom of it? 195. My assumption was wrong, the old stat was simply stuck slightly open.
