Should I Use Water or Antifreeze?

An internal combustion engine in a car, boat, or airplane produces heat, particularly if that engine runs for a long time. Engines need to remove this heat to avoid high temperatures that can reduce the lifespan of the engine or damage it beyond repair. Most engines conduct this heat transfer using a pressurized system that displaces the heat to a coolant such as water or antifreeze. When performing routine maintenance, ensure that the vehicle has a sufficient supply of water or antifreeze. Determine whether water or antifreeze best suits your needs based on cost, outside temperature, and the substance’s impact on engine components.

Water is a viable option to use as a coolant in an engine because of its ability to absorb a large amount of heat and transfer it away from the engine. Water is also readily available and cheap to acquire, so you can easily refill your vehicle if the coolant level runs low. On the other hand, using water as an engine coolant has some drawbacks.

In climates that are extremely hot or cold, water may not be the best option. If the engine temperature exceeds the water’s boiling point, then the water will turn to steam, leaving the engine unprotected. Conversely, if the engine temperature falls below the freezing point, the water may turn to ice and can crack the engine. Water and steam can be corrosive and damaging to the metal in the engine.

Antifreeze is another engine coolant option. The two main types of antifreeze are ethylene glycol-based or propylene glycol-based. Antifreeze has a high boiling point and low freezing point, so it can be safely used in all climates, and some antifreeze contains chemicals that protect metal and lubricate engine parts.

Using antifreeze has its drawbacks as well, including higher cost, poor heat-transfer efficiency and toxicity. Water is much cheaper than antifreeze and more readily available, and antifreeze is not as efficient at transferring heat as water, although the heat-transfer rate is sufficient to keep an engine cool. In addition, ethylene glycol-based antifreeze is highly toxic and can cause organ failure or even death if ingested, while propylene glycol-based antifreeze can be highly corrosive if it is not handled properly.

Instead of choosing using water or antifreeze, many people choose to use both by combining the substances into a single mixture that serves as an engine coolant that draws on the benefits of both compounds. The water-antifreeze solution has a high enough boiling point and a low enough freezing point to be used in most climates. At the same time, anti-corrosion chemicals and lubricants in the antifreeze help protect engine parts.