Yeah mine on my 95 3.1 V6 rarely moves past the first bar above the C when driving. It will move 2 or 3 more bars when idling. Was thinking it is the thermostat. With parts and labor what am I looking at spending? And does it hurt anything for it to run cool like this?

Running cool doesn't completely burn the fuel all the way causing your MPG to go down and may even cause you to fail the sniffer part of the emittions testing. Reason people shouldn't jump on the 160 degree thermostat bandwagon for "added horsepower" gain. You want car to get hot enough to burn the gas but not hot enough to warp the metal parts. you also have to warm the pistons up on the 3100 3400 and 3500 engines or you get the dreaded piston slap when the car warms up(go to youtube for 3100 piston slap)

Before I go on a tangent(too late!) how is your gas mileage? If it hasn't changed much it may be normal for the pre 97 centuries due to the gauges being less sensitive and a temperature sensor change later on to be(more sensitive). For the 97 and up we bounce between 12 o'clock and 11:45 when at operating temp.

Would running cool affect the gas mileage by much? My car usually runs around 1/4 on the temp gauge when its cold outside, even after its warmed up, and lately it seems like my mileage is lower than usual..

Not sure how you guys are there but we have a "Winter Gas Mix" here that kills MPG plus the longer warm up period idle while clearing the car off. I usualy don't idle in the winter more than 3-4 mins but this car cold loves to fog the windows making me pull over half a block to let it warm up some more. I barely give it gas till I know the pistons are pretty much expanded to normal.

It could be the winter mix.. I usually let it idle for about 10 minutes or so in the mornings before I go to school, so its usually warm when I leave. I've never had much of a problem with my windows fogging up, but my dad's 04 is horrible for it. It seemed like every time the heat was turned off, the windows would fog up within a couple minutes.

The answer is yes the gages were purposely set to read low to prevent people from freaking out over 220* coolant temps.

A week ago I turned the car on to let it warm up and came back to a cracked mirror. Good thing I have another auto dim mirror I haven't installed yet. Not even sure how that happened I didn't even touch it nor clean it in quite some time.