i think the reason might be your cooling system, check the basics. the basic would be to see if there is low coolant in your engine when it is cold and in the radiator. If that is fine then check the thermostat located in your cars engine. It might be open and not checking your cars temperature right or might need to get replaced.
If stuck open the car will run cold. If stuck closed the car will run hot.
You need to change your thermostat in the car.
open or missing thermostat
When the car is cold the thermostat is closed. When the thermostat is closed the coolant does not circulate or get in to the engine block.
Insufficient amount of coolant or thermostat not opening
No
Thermostat is gone, change it
you need a new thermostat
replace the a/c thermostat
it keeps the temperature regulated. as in, it doesn't let the engine get too cold or hot.
It will always run cold so it will run inefficiently.
Try your thermostat