Coolant (or antifreeze) protects your engine from freezing while defending components against corrosion. It plays a critical role in sustaining engine heat balance by removing heat. In a heavy-duty diesel engine, only one-third of the total energy produced works to propel the vehicle forward. An additional one-third is removed as heat energy by the exhaust system. The remaining one-third of heat energy produced is taken away by the engine coolant. This heat removed by the coolant provides a balance in the removal of engine heat that is critical in ensuring that the engine operates properly. Overheating could result in accelerated deterioration of the oil and the engine itself.