Around one-third of heat produced by the energy in gasoline is converted into work that powers the car. Another third goes out the tailpipe in the form of exhaust, while the remaining third is absorbed by the engine’s coolant. This last bit of heat is dispersed into the air passing by a car’s radiator.
Poor or low quality coolant can freeze, blocking the liquid’s flow and preventing it from doing its job of dispersing your engine’s heat, possibly causing a nasty overheating situation, even if the air temperature is -25° Cesius. Frozen coolant can also expand to crack water pumps and radiators.
Modern coolant is generally mixed with equal parts water and provides freezing protection down to -40° Cesius. Oddly, undiluted coolant will freeze at roughly -15° Cesius as it’s the chemical reactions with water which provide the frigid protection.
Today’s chemistry all but assures coolant a long lifespan. As a bonus, many manufacturers cook up a few additives designed to prevent corrosion forming inside the cooling system. There are three basic types of coolant chemistries available for use in modern automobiles and, no, they are not always immediately identifiable by their colour.