That information really doesn't mean anything to me.

The coolant temp sensor and engine computer use real numbers like 180º or whatever. The cluster is not as accurate as the temp sensor it self.

Get a scan tool that can read live data and see what the real temps are.

Installing a cooler thermostat is very common so don't rule that out, someone could have already done that. A stock thermostat is going to stay around 190-205 degrees.