The coolant in your car's radiator prevents the risk of overheating and helps your engine maintain a consistent operating temperature. You should check the coolant levels in your radiator regularly and be sure there are no contaminants floating in the system. Keep fresh coolant on hand for those times when you need to top off the radiator or if you want to drain the system and replace it.
Pour one gallon of the antifreeze of your choice into a large bucket or large mixing jug.
Pour one gallon of distilled water into the bucket or mixing jug.
Mix them together thoroughly and use the coolant blend in the car's radiator. Store the coolant blend in a large, tightly sealed jug.
Do not use tap water when creating a coolant blend or topping off your radiator in an emergency situation. Tap water contains minerals that may cause corrosion within your cooling system. Distilled water is the safest form to use. Too much water or too much antifreeze in the cooling system can result in inefficient cooling, possible overheating and corrosion concerns within the radiator, particularly with the aluminium components.