Coolant: What it Does and Why It’s Important

Without radiator coolant, an auto engine would overheat extremely fast, leading to mechanical breakdown and engine failure. While oil may be the lifeblood of a car’s engine, coolant is like the water that helps to dispel heat. In fact, coolant mixes with water in a car’s radiator. It prevents the water from freezing and boiling given the extreme temperatures it is exposed to. Considering the amount of heat energy generated by burning gasoline within an internal combustion engine is between 19 and 20,000 BTUs per gallon, the engine’s cooling system is greatly relied upon to ensure the car functions properly.

What Coolant Does

Coolant consists of a mixture of water and antifreeze that is stored in the car’s radiator. A good rule of thumb is to mix them 50/50, but more antifreeze in the mix increases the boiling point and decreases the freezing point. Generally speaking, a 50/50 mix is more than adequate for the kinds of conditions the engine faces. As the engine burns the gasoline, nearly 1/3 of the energy produced ends up as waste, either in the form of excess heat energy or exhaust. The heat energy that remains in the engine cannot simply be allowed to sit and fester. That is how overheating and eventual breakdown happen.

Why Coolant is Important

Without coolant, the heat produced through constant internal combustion would destroy the engine very quickly. Water alone is not entirely adequate to keep the system cool, for the high temperatures inside the motor would eventually boil it off. In time, the water in the system would evaporate entirely. Likewise, in very cold weather, the water would freeze when the car sat idle, rendering the cooling system useless. For these reasons, the mix of antifreeze is vital to the proper working of the coolant system.

The coolant in a car’s cooling system needs to be inspected every so often to protect against corrosion. While the main component of antifreeze, ethylene glycol does not expire, any additives to inhibit corrosion eventually do. This makes it a requirement that you change the coolant every 30,000 miles. The radiator, too, must be in good working order. If rust builds up, the heat exchanger may fail to function properly and lead to problems down the road.