Antifreeze is a substance that is added to a liquid to lower its freezing point. Antifreezes are used in compounds that remove ice or prevent it from forming, and in refrigerants and heat-transfer fluids. This article discusses automotive antifreezes, which are added to an automobile engine’s cooling system.
An automobile engine operates at extremely high temperatures. It is cooled by fluid circulating through a cooling system. This prevents the engine from overheating, which can result in engine damage. Previously, water alone was used in the cooling system during the summer, and antifreeze was added to the water during the winter. Today, however, automobiles are designed to use a mixture of equal parts of water and antifreeze as the coolant the year around. Antifreeze prevents the water from freezing in cold temperatures. Modern antifreezes also raise the boiling point of the water. The cooling system therefore can operate at higher temperatures without the risk of boiling. The cooling system also operates more efficiently at higher temperatures.
Such materials as kerosene, honey, salt water, and methyl alcohol were once used as antifreezes, but these substances can damage a car’s engine. Today, most automotive antifreezes are composed chiefly of a liquid compound called ethylene glycol (see Glycol ). Automotive antifreezes also contain chemicals that protect the metal parts of the engine’s cooling system from corrosion.
