Coolant, technically called engine coolant, is the liquid that circulates through your engine and radiator to maintain the desired operating temperature. Often mistakenly called antifreeze, coolant is a mixture of water and antifreeze, which is a liquid that prevents not just freezing but also boiling, either of which could cause the engine to overheat. (Coolant is not to be confused with refrigerant, the pressurized gas that allows the air conditioning to keep the cabin cool.) Engine coolant should be checked according to the manufacturer’s recommendation (check your owner’s manual) to ensure there’s enough, and that it’s in good condition. A replacement interval is also provided in the manual, and it varies with the make and model.
