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Antifreeze vs. Coolant: What’s The Actual Difference?

in Ownership
Antifreeze tank in car

Source: Pixabay

Extreme hot and cold temperatures can significantly affect your car’s engine, highlighting the importance of caring for your vehicle’s cooling system. With extreme temperatures, there’s a good chance that your car’s engine will experience a seizing-up effect, and it may stop running altogether and require expensive repairs.

To ensure a fully functioning engine cooling system, every car owner needs two products: antifreeze and coolant. You may have heard the terms antifreeze and coolant used interchangeably at some point, leading you to think they’re the same thing.

Well, not exactly.

For today’s post, we shed some light on the differences between antifreeze vs coolant. Not confusing one with the other is vital because using the wrong product will have detrimental effects on your engine.

The Main Difference Between Antifreeze Vs Coolant

Antifreeze vs coolant, what’s the core difference between the two?

Simply put, coolant is the product you put inside your vehicle, while antifreeze is one of the active ingredients of a coolant mixture. Antifreeze is generally made up of ethylene glycol or propylene glycol and is the primary ingredient of this product. Mixing the antifreeze with water creates a cocktail which is what’s referred to as coolant for a vehicle’s cooling system.

Typically, the coolant product comprises a 50-50 mix of antifreeze and water. The 50-50 mixture provides enough cooling for engines that run at more than 200 degrees, while the antifreeze properties prevent freezing for cold temperatures below 30 degrees. However, in cases of extremely cold temperatures, the mixture can be as high as 70% antifreeze.

What’s the Purpose of Antifreeze?

During freezing temperatures, the liquid expands and crystallizes when it freezes. Once the liquid inside the system freezes, it’ll expand and may crack the engine blocks and other components. This is where antifreeze comes in handy.

Antifreeze is the substance responsible for lowering the water’s freezing point. As mentioned, the main active ingredient of antifreeze is ethylene glycol or propylene glycol. Antifreeze is a critical component of the coolant cocktail because it prevents liquids from freezing inside your engine’s cooling system.

Antifreeze comes in many different colors like pink, orange, green, etc. It may also come in various chemical formulas used in certain vehicles. The different types of chemically-formulated antifreeze shouldn’t be mixed with each other. Refer to your vehicle’s owner’s manual to know which kind of antifreeze to use.


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What’s the Purpose of Coolant?

What we call the coolant is the final product that comes out when mixing water and antifreeze with a 50-50 ratio. The primary purpose of coolant is to transfer heat and prevent engine damage due to freezing or boiling.

The coolant resides in the radiator when the engine is off. Once the engine is started, the coolant gets pumped via the engine’s passageways to distribute heat, and then it goes back into the radiator. In the radiator, the coolant is cooled by fresh air so it can be circulated back to the engine again. When you turn on the car heater, some coolant amounts are brought into the core. The coolant provides heat into the heater core, which blows warm air into the cabin.

Earlier, we’ve discussed what happens when engine fluid freezes, but what happens when the coolant boils? If boiling occurs, the formed vapors can’t transfer heat properly. This may result in the engine metals melting because the coolant isn’t kept in contact with specific areas that must stay cool.

Many modern vehicles have tight engine compartments that don’t have ideal airflow. Thus, the engine would overheat in minutes without a properly working cooling system.

Antifreeze Vs Coolant: Safety Precautions

Using a suitable coolant and antifreeze is a must for maintaining your vehicle’s cooling system. Thus, if you’re looking to top off or replace the coolant on your own, ensure you’re buying the correct brand and blend for your vehicle.

The best tip in this regard is to read the owner’s manual about the correct coolant type to use and examine the labels closely before buying any product. Most stores have pure antifreeze (unmixed) and premixed ones (usually 50-50 ratio), so it helps to read the labels.

Another safety tip to remember is to avoid mixing coolants of different colors. Antifreeze or coolant comes in different colors like yellow, pink, blue, and green – each color corresponds to a particular formula of the coolant/antifreeze.

One of the biggest mistakes you could make when topping off is to mix two different types or colors of antifreeze. While the concoction won’t necessarily explode, it will form a thick, jelly-like substance that prevents the adequate flow of fluid. This may lead to the engine overheating and other problems that will earn you a hefty bill at the shop.

Antifreeze Vs Coolant: FAQs

How often should I replace my engine coolant?

Most experts and professional mechanics recommend changing your coolant every 30,000 miles. Some manufacturers advise replacing the coolant for the first time at 60,000, then every 30,000 after that. Check your owner’s manual to know your vehicle’s specific requirements.

Can you mix antifreeze?

The only substance you want to mix antifreeze with is water, ideally with a 50-50 ratio. Otherwise, it’s never a good idea to mix different types or colors of antifreeze. Please keep it simple and follow the manufacturer’s recommendations.


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What happens when I use the wrong coolant/antifreeze?

Using the wrong coolant or a bad mixture can severely limit the special additives in the fluid, which can lead to radiator corrosion. As a result, it may also damage the other components, including the water pump, radiator, hoses, and cylinder gasket. Worst case scenario, the engine will be damaged, resulting in astronomical repair bills.

How do I know if I need a coolant refill?

One of the classic signs is the higher than average heat produced while the engine is running, so check the temperature gauge readings. Another symptom is when you notice some rusting on the coolant reservoir. In addition, be on the lookout for a distinct “maple syrup” smell coming off your engine.


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