How Long Does Antifreeze Last? (Does It Expire? Explained!)

Antifreeze, also known as coolant, is a mixture of ethylene or propylene glycol and water. In general, this mixture circulates in the cooling system of an engine to keep it from overheating. One of the many worries of car owners is how long this mixture can serve their cars. Thus, you may also ask:

How long does antifreeze last, and does it expire? Antifreeze does not expire, and you can keep yours for years as long as you have it stored in its original container. Thus, you won’t have to worry about using your stored coolant after years of keeping it. Even if the container is already opened, you can still use it after a long time.

Due to the indefinite shelf life of antifreeze, you won’t have to worry about opening one and using it immediately. One thing to note is that coolants need to be replaced after a while once you used them. Thus, you’ll likely need to store yours for years without usage. 

In this article, we’ll walk you through some of the questions related to this matter. This way, you can understand the properties of antifreeze and how you can use and store them to use them in the best way possible.

Without further ado, let’s get into it!

How Long Does Antifreeze Last

Does Antifreeze Expire?

No, an antifreeze does not expire, and you can use a stored antifreeze even after years of staying on your shelf or in your garage.

Unlike other products, coolants or antifreeze have an indefinite shelf life. In short, you can store even an opened bottle of antifreeze and keep it for years and then use them after.

Some mixtures and products tend to expire after a certain period. Thus, you may wonder if it’s also the same with antifreeze.

As long as you keep the coolant in its original container and place it in a secured place where no other liquid or particles would pollute it, then it can last for a long time.

One thing to note is that antifreeze is a coolant that’s not yet mixed with water. So you’ll need to add water to it before placing it in the cooling system of your car.

Some products are already mixed with water so that you can add them to your car. Now, these types of products may not last as long as a pure unmixed antifreeze. Even so, both products will last for years as long as you store them properly.

Now, while antifreeze doesn’t expire, it’s only applicable for storage. In addition, once you have used an antifreeze, it tends to suffer pollution in a car’s cooling system. Thus, you’ll need to replace such coolants after a certain period, or an issue with the cooling system or the engine occurs.

Does Antifreeze Go Bad Sitting on the Shelf?

As I mentioned earlier, antifreeze has an indefinite shelf life. Thus, if you let your antifreeze sit on your shelf, you can still use it even after several years.

One thing to note is that if you plan on keeping it for a long time, you’ll want to maintain it in its original container.

The reason is that you’ll want to avoid any possible fragment or particle from reaching the liquid and diluting it. 

Since you’ll need to replace your coolant once in a while, it’s more likely that you won’t have your antifreeze stored for several years (unless you forget about it). 

Still, even after years of sitting on the shelf, your antifreeze won’t go wrong. But, as I also mentioned earlier, antifreeze can go wrong once you use it on your car.

An antifreeze can go wrong in a car due to many reasons. However, in general, it will be more of pollution or wear over time of use. In such cases, a replacement would be necessary to keep your cooling system in good condition.

Does Antifreeze Lose Its Effectiveness?

Antifreeze does lose its effectiveness. After some use, this mixture tends to lose its effectiveness, although it’s not evaporating.

As I mentioned earlier, coolants are mixtures of ethylene glycol and water. Therefore, the ethylene glycol may not evaporate due to excessive heat or solidify due to excessive cold. Still, the chemical can lose its effectiveness over time of use.

This chemical loses its effectivity quicker when more water is added to the coolant over time. 

The coolant needs a 1:1 ratio of water and ethylene glycol. Thus, if you only add water to your cooling system, it will dilute your coolant and lose effectiveness.

For this reason, your best move is to replace your coolant by adding another mixture. This way, you can maintain your cooling system’s condition and continue its protection against overheating and freezing.

old antifreeze

How Do I Know if My Antifreeze Is Still Good?

If you store your antifreeze on a shelf, you can know that it’s still good even after years of unuse. Now, if you want to check if the antifreeze in your car is still good, you can check for signs to see if you already need to replace it.

For instance, the common issues that can be a sign of a lousy antifreeze are the following:

Warmer temperature

One of the best ways to see if your antifreeze is still good is the temperature. Since your antifreeze keeps your temperature from overheating and freezing, you can tell it’s still good if it maintains a reasonable temperature. Otherwise, you’ll want to replace it soon.

Orange and green fluid leakage

Most antifreeze has an orange or green color. Thus, if you see puddles or leaks of orange or green fluid under your car, you’ll want to check it soon. Otherwise, your antifreeze is likely to be in good condition.

Grinding sound

A grinding sound or noise can happen under your car’s hood when your antifreeze or cooling system has problems. Thus, you’ll want to check it out soon and see if your antifreeze is still good or needs replacement.

Rust particles

Rust is the common pollutant of antifreeze. Thus, if you see any rust particles in your coolant, you’ll want to solve that problem soon. On the other hand, if your coolant still looks clean, then it’s still a good one, and you don’t need to replace it yet.

Presence of steam coming out

In most cases, a failing cooling system can start producing steam in the car. Thus, if you see steam coming out of your car, you may want to check if your antifreeze is the cause. If it’s not from the cooling system, then your antifreeze is still good.

Years of use

In general, you need to maintain an excellent cooling system, and so you’ll want to have it checked every 100,000 miles you drove. If you have an older model, you may need to have it checked more often. Thus, if you reached the said limit, you can assume that your coolant isn’t suitable, and you’ll need to replace it soon.

Summary

In a nutshell, antifreeze can last for years as long as it’s stored properly in its original container. Thus, you won’t have to worry about using it after several years of storage. But, unfortunately, now, while you can use antifreeze after years of storage, you can’t keep the same antifreeze for years in your cooling system.

A coolant can fail once it starts working in a car. Thus, you’ll need to understand when to replace it and when it’s still in good condition. 

In general, antifreeze is responsible for preventing your car from overheating and from freezing. Thus, you’ll want to have it always checked and store it properly if you want to have a spare for it.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more