My truck isn't running at normal running temp. It doesn't go past what is shown in the pic, and if my truck is stopped ( at a drive thru or something ) the temp will drop a noticeable amount. Any ideas? Could it be my tstat? Oh and it has been around 0 to 5*C the past few days, so it's not like it is freezing cold.

 

Thermostat would be a good place to look.
My truck has always shown a low reading on the IP, even in the middle of summer in AZ but it never really deviates much.

 

I had the EXACT same issue last week. I put in a new thermostat and the problem was fixed!