Keep in mind:
* Gauges aren't always accurate: The gauge in the car is just an indicator. An accurate reading requires a mechanical temperature gauge or an infrared thermometer aimed at the thermostat housing.
* Conditions matter: Factors like ambient temperature, driving conditions (heavy load, stop-and-go traffic), and the condition of the cooling system will all influence the actual operating temperature.
* Thermostat: A malfunctioning thermostat can cause temperatures to be too high or too low.
If your Coronet's temperature consistently runs outside this range, especially towards the higher end, investigate potential issues with the cooling system.