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Antifreeze vs Coolant (What's the Difference?)

When it comes to maintaining the health of your vehicle's engine, it's important to understand the difference between antifreeze vs coolant. Coolant plays a crucial role in regulating the temperature of your engine.

Antifreeze is usually pure ethyl glycol, coolant is the mixture of distilled water and antifreeze, coolant comes in different ratios of antifreeze and water.

In this article, we will discuss the differences between engine coolant and antifreeze and understand what they do in your car.


Table of Contents:

a coolant reservoir in a car

Should I Use Antifreeze or Coolant?

The answer to this question depends on the climate in which you live and the type of vehicle you drive. In colder climates, it's important to use a coolant that has a lower freezing point.

In warmer climates you don't need as much antifreeze, sometimes you won't need any antifreeze at all and could use pure distilled water as your vehicles coolant.

What Is Antifreeze?

Antifreeze is a liquid that is added to the coolant system of a vehicle in order to prevent the water in the system from freezing during cold temperatures. It is usually pure ethylene glycol, which is a colorless, odourless liquid that is toxic to humans and animals if ingested.

Antifreeze also raises the boiling point of water, which allows the engine to operate at higher temperatures without the coolant boiling. It also reduces the freezing point of water, which prevents the coolant from freezing in the engine.

What Is Engine Coolant?

Coolant is a mixture of antifreeze and distilled water that is added to the engine in order to regulate the temperature.

There are two main ratios of water to antifreeze that are commonly used; 50/50 and 70/30.

  • The 50/50 ratio is a mix of equal parts antifreeze and water, which is suitable for use in most climates.

  • The 70/30 ratio is a mix of 70% antifreeze and 30% water, which is more appropriate for use in very cold climates.

In hot countries the ratio of water to antifreeze may be very high, or they may even use pure water as they do not need to worry about their vehicles engine coolant freezing.

Difference Between Antifreeze vs Coolant

The main difference between antifreeze and engine coolant is that antifreeze is a pure chemical, whereas coolant is a mixture of antifreeze and water.

  • Antifreeze is added to the coolant system in order to prevent the water from freezing, and to raise the boiling point of the coolant.

  • Engine coolant is a mixture of antifreeze and water and is added to the engine in order to regulate its temperature.

Can I Just Add Antifreeze to My Car?

You can technically add antifreeze to your car's cooling system, but it is not recommended to add antifreeze to the cooling system if the system already contains coolant.

You should instead use a pre-mixed coolant, which is a combination of antifreeze and water that is already formulated. It is always best to check the owner's manual of your vehicle or consult a mechanic for specific recommendations for your car.


Choosing the right antifreeze and engine coolant for your car is crucial for maintaining the health of your engine.

Understanding the difference between antifreeze vs coolant fluids, and knowing the appropriate ratio of antifreeze to water for your climate, will help ensure that your car engine runs efficiently and lasts for many years to come.

Always consult your vehicle's owner manual or a mechanic for specific recommendations for your vehicle.


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