welcome to the sucky gauge world of dodge!!!!!! this is normal as far as dodge gauges go

 

Nothin to do with gauges it the t-stat.

This guy has the best one a guy can get.

There is a 180* t-stat you can buy but takes longer to warm up but it does hold 180* all day long. In my 12v i'll run nothin but the cycling t-stat from cummins.