Car engines run remarkably well using combustion fuels and oil for part lubrication. But friction still occurs between the moving parts, leading to heat buildups. If the climbing temperature is not dampened or dissipated, the engine will overheat and stop working. As a result, engine coolant needs to flow sufficiently to keep an engine cool.
Engine coolant has to remain warm enough to stay fluid so it can be pumped through an engine. Water alone won’t work; it will freeze too quickly. Coolant with a 50/50 mix of water and ethylene alcohol (anti-freeze) can function at temperatuares as cold as negative 36 degrees Fahrenheit.