Engine not reaching operating temperature

The gauge should run in the middle of the range, or somewhat close to there anyway. The temp gauge on my Challenger always has, and so does the rallye temp gauge in my Duster.

If you just bought the car, have you ever seen the temp gauge needle move? If not, I'd check all the electrical connections first to make sure its even hooked up. Then try the sending unit. If the engine is running fine and seems to be getting warm, it's more likely to be a wiring/sender/gauge issue. Does the heater blow hot air after the car warms up? If it does, its probably not the themostat.