Should a car be filled with water or coolant?

[Daniel]

An automobile radiator should be filled with coolant, which is a year-round liquid unaffected by seasonal changes, ensuring high-quality performance. Although using water as a substitute for coolant may cause some damage to the cooling system, short-term use will not harm the thermostat. Functions of coolant: Coolant, including glycerol-based and ethylene glycol-based types, serves to cool the engine. Also known as antifreeze, insufficient coolant can hinder proper engine cooling, leading to operational failures. Coolant effectively prevents engine malfunctions, avoids radiator overheating, and provides long-term protection for water temperature, making it suitable for year-round use. Coolant replacement cycle: Coolant should be replaced annually. Its characteristics include a high boiling point and excellent stability, preventing scale formation in the radiator. Insufficient coolant prevents the engine from cooling down promptly, resulting in excessive component gaps and impaired functionality.