Can You Add Water to the Car Radiator Coolant?

[LeOlive]

You should not directly add water to the car coolant, as doing so will lower the boiling point of the new coolant mixture, which may cause the car to overheat. The main component of coolant is ethylene glycol, which has excellent thermal stability—preventing freezing in winter to protect the engine and cooling the engine in summer. This ensures the engine operates at an optimal temperature year-round, an effect that cannot be achieved by using water alone. Coolant serves multiple purposes, including antifreeze, cooling, corrosion prevention, and scale inhibition. Although coolant contains water, it is specifically soft water (distilled water), which has undergone deionization and softening treatment. If the engine coolant level is low, you can add soft water, but be cautious about the quantity—adding too much can alter the coolant's boiling and freezing points. Reasons why you should not add water to car coolant: The primary function of antifreeze is to prevent scale formation. Adding water to antifreeze can lead to scale buildup in the engine, clogging the pipes and affecting performance and lifespan. Mixing water with antifreeze may cause engine scaling, which can block the cooling system, disrupting normal operation and shortening the engine's service life. The water in antifreeze is soft and must be mixed according to specific standards. Therefore, it is not recommended to add water to car antifreeze. Its main role is to circulate within the engine cooling system, carrying away excess heat generated during operation, ensuring the engine runs at the proper working temperature.