What are the components of coolant?
2 Answers
Coolant is composed of water, antifreeze, and additives. Depending on the components, it can be classified into alcohol-based, glycerol-based, ethylene glycol-based, and other types of coolants. The full name of coolant is antifreeze coolant, which is a coolant with antifreeze function. It can prevent the coolant from freezing and cracking the radiator or damaging the engine cylinder block when the car is parked in cold seasons. Antifreeze is not only used in winter but should be used all year round. In normal car maintenance, the engine antifreeze should be replaced every year. Currently, almost all coolants used in engines domestically and internationally, as well as those available in the market, are ethylene glycol-based coolants.
I always carefully check the ingredient list before changing the coolant for my car. The basic components of common coolant are approximately 50% ethylene glycol and 45% deionized water, with the remaining being key additives—corrosion inhibitors like silicates and phosphates, specifically designed to prevent rust and corrosion on engine metals; antifoaming agents to avoid bubble formation in the pipes which could affect heat dissipation; and pH buffers to maintain stable acidity levels. Some newer coolants use propylene glycol instead of ethylene glycol, which is less toxic and more environmentally friendly. The color differences mainly depend on the dyes used, such as green with chromates and red with organic acid technology additives. Remember that the effectiveness of the components degrades over time, and it's generally recommended to change the coolant every two years; otherwise, the radiator may accumulate scale. Friends in northern regions should opt for formulas with higher ethylene glycol concentration for better antifreeze performance.
