Though considered similar products, antifreeze and coolant serve different purposes. It is a concentrated product that is based on glycol and contains inhibitors. Some form of additives has to be diluted with water to the desired concentration before use. Importantly, the diluted form of automotive antifreeze is known as a coolant. One may purchase a pre-mixed coolant that is ready to use a solution of water and the additive. The solution mainly consists of ethylene glycol, which prevents the coolant from freezing within the radiator, fosters the lubrication of the water pump, and impedes corrosion. Coolants are used in an automotive cooling system to attain efficient engine operation. Notably, antifreeze works best when diluted with water. Antifreeze vs coolant is a common debate among automobile owners as some consider the two products similar, while others comprehend their variances.