Coolant vs Antifreeze, What's the difference?

You may have heard that you need antifreeze, coolant, or both and wondered, "What's the difference?!" The terms are often used interchangeably, which can cause a lot of confusion. That confusion is problematic because using the wrong product can have detrimental effects on your vehicle.

Let's take a closer look at each and which one you need to use.

What's the Difference Between Coolant and Antifreeze?

Put simply, coolant is the product you put into your car, while antifreeze is the active ingredient in coolant that requires dilution.

What Is Antifreeze?

Antifreeze is a substance that lowers the freezing point of water. The active ingredient is typically ethylene glycol or propylene glycol. It's helpful because it can prevent liquids from freezing within a system and causing damage. How? When water freezes, it expands and crystallizes. Antifreeze makes it harder for the molecules to join together and crystallize, causing the freezing point to drop.

What Is Coolant?

Coolant is a mixture of antifreeze and water, often a 50/50 ratio. It's pumped through the engine and heater core of a vehicle to absorb excess heat. Then, it goes through the radiator to dissipate the heat to the outside air. The coolant continuously runs through the system but breaks down over time. It should be changed every 30,000 miles or so to prevent corrosion and ensure proper temperature control.

Why Do You Need to Dilute Antifreeze?

Antifreeze needs to be diluted before putting it into your vehicleWinter Snow Driving Safety Tips Blog for a couple of reasons.

Lower Freezing Point

First, despite the name, 100% antifreeze will actually freeze before coolant at temperatures between 0 and -5 degrees Fahrenheit. Coolant with a 50/50 mixture has a freezing point of -35 degrees FahrenheitR Advice Car Maintenance Antifreeze Coolant Basic Information Shop.advanceautoparts.com. Further, a 70/30 mixture of antifreeze and water drops the freezing point lower to -84 degrees Fahrenheit.

Higher Heat Transfer Capability

Second, pure antifreeze is not as effective at transferring heat out of the engine and heater core. When you are driving on a hot summer day, this becomes more important to avoid overheating your vehicleHow To Drive In Extreme Heat Driving Resources. Coolant at a 50/50 mix has a boiling point of 223 degrees Fahrenheit, which is higher than water.

Better Suspension of Additives

Third, antifreeze has additives in it such as silicates, nitrates, and phosphates to protect against corrosion. Water helps to suspend those additives. Without water, the additives will often settle into your vehicle's system. When that happens, you lose protection against corrosion.

Can You Use Water in Place of Coolant?

Water can help to keep your engine cool, but it doesn't work nearly as well as coolant. Water boils faster and at a lower temperature than coolant and will freeze at a much higher temperature. While distilled water could be a bandaid in an emergency, it's always better to use the proper coolant to avoid costly problems.

Stay on the Road by Taking Good Care of Your Vehicle

Now that you know the difference between antifreeze and coolant, always ensure your vehicle is running with the right coolant for your system. This will help to keep it in good working order for years to come.

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