Can engine coolants be used undiluted?
No. All engine coolants on the market with the exception of ready-mixed products have to be diluted with water before use. They have to be diluted in order to protect engines from freezing and corrosion. Undiluted coolants freeze at –13 °C, which would damage the cooling system and engine. Engine coolants have a lower heat capacity than water and undiluted coolants absorb less heat at temperatures above 0 °C, which would cause the engine to overheat.
