Thermostats: Opening and closing temp. Options

[RobbMeeX]

So I had been having a sneaking suspicion that my thermostat wasn't up to snuff. My car (95 Toyota Celica ST, 234k) never overheated, but temp fluctuated more than I would like (I don't want any fluctuation from city to interstate). So I researched and found the Stant Superstat ($10, made in America) and bought one for my car. I tested it on the stove. 180°f (82°c) open AND close. Tested good so I replaced it. Old one had no sign of anything funny UNTIL I put it on the stove. With my temp gun I measured opening temp at 170°f (76°c) and closing temp was not until 120°f (49°c)! That means when the car is warm its never getting to a good efficient temp. I have been getting 31mpg and have a 340 mile trip to take in a few hours. I hope to see an improvement in mpg based on the new temp. This particular tstat comes with a lifetime warranty so I can replace it in a few years if I sense funny business.

Stant# 45758