Coolant, also known as antifreeze, antifreeze, water tank treasure, etc. The main function is to protect the normal and good operation of the engine, circulate in the engine water tank, play an anti-freeze, anti-boiling, anti-rust, anti-corrosion and other effects, most of the color of the antifreeze is red or green, to observe whether it leaks, or is different from other liquids of the engine, to avoid confusion.

Engine coolant, the common is ethylene glycol - aqueous solution, which is the basis. Due to the requirements of modern automotive processes, many additives are added to the coolant to protect a wide variety of engines. The difference in these additives causes the coolant to divide into several camps.