Cavitation corrosion of cylinder liners in heavy duty engines can be one of the significant limits in engine operating time between overhauls. In both laboratory and engine dynamometer studies, engine coolants based on propylene glycol (PG) have performed better than similar formulations based on ethylene glycol with regard to cast iron cavitation corrosion. The performance of PG base coolant in all other aspects of coolant use was equivalent or superior to both industry standards and existing ethylene glycol (EG) products designed for use in heavy duty engines. Additionally, propylene glycol is cost competitive, readily available, and less toxic compared to ethylene glycol. A propylene glycol base engine coolant is described which assists the heavy duty user in solving many current problems related to cooling system servicing and engine life.