Water is a good coolant and is used to cool the engines of cars, buses, trucks, etc. It is because water has a

Water is widely used as a coolant in internal combustion engines for cars, buses, and trucks primarily because it possesses a high specific heat capacity. Specific heat capacity is the amount of energy required to raise the temperature of a substance; water's high value (approximately 4.2 J/g·K) means it can absorb a significant amount of waste heat from the engine with only a minimal increase in its own temperature [1]. This property allows it to move heat more efficiently away from engine components to the radiator compared to other liquids [1]. While additives like ethylene glycol are used to raise the boiling point and prevent freezing, pure water remains the superior component for heat absorption due to this thermal property. Other factors like surface tension or expansivity do not contribute to its effectiveness as a cooling medium in this context.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 26: Tropical Cyclones > The Sea Surface Temperature (SST) Is Higher In The Northern Hemisphere > p. 369