Only if it's leaking.
Example sentence - The coolant in my car was leaking out.
No. Use Coolant from honda dealership
Refrigerant - not coolant - and no, they are not compatible.
you use a car
The company that makes the all model coolant claims you can.
No
In short no. Your cars cooling system is a sealed unit therefore it should not use any coolant whatsoever no matter the ambient temperature.
Because it's attached to the engine and uses power when you turn it on. Even if it wasn't attached to the engine, anything in or on a car that takes power in some form will use fuel because ultimately it's the engine that supplies that power.
because it's used in your engine as coolant
If you are driving on the freeway, it is more economical to use airconditioning than to leave your windows open. The air rushing in through your windows causes resistance, and your car uses more gas to accelerate than the airconditioning uses. It is probably a better idea to roll the windows down if you are driving on inside roads though.
50 percent coolant, 50 percent water
No... But it increases fuel consumption