At 68 degrees Fahrenheit, the viscosity of ethylene glycol is 16.9 centipoise, nearly 17 times that of water. However, if it is heated to 140 degrees Fahrenheit, its viscosity drops to 5.2 centipoise. Viscosity is the measure of a substance's resistance to flow.
Ethylene glycol is a common ingredient in the antifreeze used in motor vehicles. A mixture of ethylene glycol and water has a lower freezing point than water alone, protecting the engine from damage caused by the expansion of freezing water. The mixture also has a higher boiling point, protecting the engine from overheating. However, ethylene glycol has a lower heat capacity than water. In order to provide the same amount of cooling, the water and ethylene glycol mix must move quickly through the automobile engine.