Green Coolant Vs Orange: Everything You Need To Know

Is there any difference between orange and green coolant? Does choosing which type of antifreeze you use really make a difference? Can you mix orange and green coolant?

These are the most common questions car owners have when it comes to choosing the right type of engine coolant. After all, choosing the right type of coolant ensures your car works smoothly while choosing the wrong type of coolant can cost you hundreds of dollars in repairs.

So, let’s set the record straight!

Here’s everything you need to know about orange vs. green coolant and the importance of coolant in general:

What Is Coolant? Why Coolant Is Important?

The engine is a powerful and expensive piece of machinery that uses friction and combustion to propel the car forward. This, in turn, generates a lot of heat.

When the car’s engine is overheating, it runs less efficiently or can even cause the engine to stop. To make matters worse, a piping-hot engine can even melt other important components of the car that are located near it. It goes without saying that this is a costly and stressful scenario that needs to be avoided at all costs.

This is where coolants come in. Coolants are liquids composed of a multitude of chemicals that are poured into a spout next to the engine itself. The coolant then runs along various veins within the engine, keeping it at the most optimal running temperature possible.

Usually, coolants are composed of either ethylene glycol or propylene, water, and some protection additives, and are usually green or orange in color.

A man pouring coolant.

Other than keeping the engine cool, the coolant also has several ingredients that have anticorrosive properties. Using the right coolant for your car can extend the lifespan of your vehicle and ensure your car’s engine is running in tip-top shape for years to come.

It is important to note that coolant is also sometimes called antifreeze. It is called this when the coolant is mixed in with water at a 50/50 ratio. This mixture means the coolant still does its job of keeping the engine cool while also ensuring the liquid does not freeze and solidify during the winter months.

It is also a great way to make a small amount of coolant go a long way.

What Happens When You Use The Wrong Type Of Coolant?

Getting the type of coolant that’s accurate for your car’s age and model is essential if you want to avoid a very expensive mistake. Each type of coolant comes with a very specific cocktail of chemicals that can either help or destroy your engine.

Using the wrong type of coolant can cause rust and corrosion to form faster, damaging the engine in the process. It can also harm other components like the radiator, water pump, radiator hoses, cylinder gasket, and more.

In certain situations, you can actually use simple water as a coolant but this is nowhere near advisable. In the winter months, the water could freeze and solidify, and in the summer months, the water could evaporate – making the engine even hotter and leading to engine failure. Water is more of a bandage solution for an overheating engine when you have no coolant on-hand.

We will go into detail below about how to tell specifically which type of coolant is best for your car. However, keep in mind that the advice of an auto professional is always preferable.

Orange vs Green Coolant

Now that you’re up to speed about what coolant is, why it’s important, and what happens when you use the wrong type of coolant, now let’s talk about the real reason why you’re here: the difference between green coolant and orange coolant.

In a nutshell, green coolant is used mainly for older cars, those models older than the 2000s era, or cars that passed a certain mileage. Orange cooler, on the other hand, is used mainly for newer models of cars or those who still have a lot more miles left to go.

With this in mind, it’s time to talk about specifics.

Green Coolant

Older models of cars contain a lot of steel and copper components in their cooling systems. As such, they need a coolant that does not react negatively to these metals and protects them from corrosion.

Enter green coolant/antifreeze!

The main component within this type of coolant that sets it apart from the orange coolant is Inorganic Additive Technology (IAT). This is a compound that possesses silicone and phosphate mixed with ethylene glycol and propylene glycol.

The inclusion of phosphate is necessary here. Whereas the other ingredients regulate the car’s temperature, phosphate flushes out grease and oil. It also softens water, making it pass through the veins of the engine more easily.

The important ingredient is silicone, which acts as a sealant for metals. It provides the interior of the engine with a nice coating that protects it from wear, tear, and oxidization.

Finally, propylene glycol and ethylene glycol is the primary cooling component of the mixture. It raises the boiling point during hot conditions and lowers the freezing point during cold conditions.

As stated above, if your car is older than the early 2000s, it is highly likely that it will require green coolant to keep the engine cool.

Orange Coolant

Orange coolant is the type of coolant that’s typically used for newer models or younger cars. These cars do not boast the same amount of metals that older models do and their engines contain nylon and aluminum.

Although orange coolant essentially fills the same roles as green coolant does, it can be considered the milder of the two. The chemical compounds found in orange coolant protect the parts that are made of metal but also make it a point to not harm any of the non-metallic parts as well.

The main mixture found in the orange coolant is Organic Acid Technologies (OAT). The main acid found in this mixture is carboxylates, which help to reduce corrosion. This element only interacts with metals, preventing rust while keeping nylon and other non-metallic materials damaged.

The transition from copper and steel to nylon and aluminum began in the 90s when car manufacturers were looking for a way to cut back on metal usage and save costs.

The only downside car owners face when using orange coolant is that it tends to allow oxygen in when its levels get low. The presence of too much oxygen in the engine can lead to oxidation or rust. This means that the car owner should always ensure that the system is full all the time.

How To Know Which Type Of Coolant Your Car Needs?

There are several ways to know which type of coolant is best for your car. The most reliable and full-proof method is to simply read the user’s manual. There should be a section there that tells you which type of engine coolant is best for your vehicle.

As a rule of thumb, most cars made before the 2000s will generally require green coolant while cars made after that will require orange coolant or other variants. If you want to be extra sure, asking a professional about it is a simple and safe way to avoid making a costly mistake.

When buying coolant, always read the label first. Deciding based on color alone is not enough since some variations of modern coolants won’t always be color orange. Some of them are pink, blue, or even green!

Expert Tip: When buying coolant for older cars, be sure to look for the Inorganic Additive Technology (IAT) on the label. For newer cars, look for Organic Acid Technologies (OAT) or whatever mixture the user’s manual recommends. The last thing you want is to waste money on the wrong coolant.

Is It Okay To Mix Coolant Types?

The short answer to this question is NO. If it is not advisable to use the wrong type of coolant for your car, it stands to reason that mixing two different types of coolant together is equally problematic.

Many car owners make this common mistake, thinking that they can get the best of both worlds. The exact opposite though tends to result from mixing coolants.

Mixing orange and green coolants together leads to a chemical reaction that causes the resulting liquid to turn into jelly. The gel does not move through the engine the same way liquid does, thus cannot cool the engine efficiently. The car will overheat and the engine will likely fail.

Furthermore, the compounds found in either green or orange coolant can damage the interior of the engine. The overheating of the engine can also cause damage to the other components of the car. This means you’ll be facing a painfully large problem that can cause you anywhere between $500-$1000 depending on the affected parts.

The only thing that you can mix the coolant with is water, which car owners do in a 50/50 ratio.

Why You Should Flush Your Coolant?

Coolant, like any other chemical, does not retain its effectiveness forever. There will come a time when the coolant, whether green or orange, will no longer be able to do its job and keep the engine cool. When this happens, you need to flush the old coolant out and replace it with a new batch of coolant.

Opening the radiator cap.

If you don’t flush and replace the coolant, you run the same risk as you would if there was no coolant at all. The engine will overheat and eventually fail while also causing damage to the other parts of the car.

How Often Should The Coolant Be Flushed?

The good news is that you don’t have to worry about flushing your coolant very often. Depending on the type of coolant, you would only have to flush it every 2-5 years or when the care reaches a certain mileage, whichever comes first.

The green coolant tends to remain effective for about 3 years or 35,000 miles. The orange coolant tends to last for 5 years or 150,000 miles. Newer models of cars and coolants are being made to last even longer than that.

Another good way to know if you need to flush your coolant is by checking it the next time you have your oil change. If you see that the coolant has taken on a rust-like color, then it’s likely that the coolant is no longer effective and needs to be flushed.

If it looks milky or murky in color, then it’s possible that the engine oil is leaking into the coolant somewhere within. This is very dangerous and should be taken to a professional immediately.

You can also place a little bit of the coolant between your thumb and forefinger to check. If it feels grainy or sandy when you rub it, the system might need to be flushed.

How To Flush Your Coolant?

If flushing your car’s coolant is a new concept for you, then:

Step 1: Preparations

Make sure your car is on level ground and gather all the items you’ll need such as the coolant flush product, the new coolant, and a container to catch the old coolant.

Step 2: Drain

Once the engine is cool enough, open the hood, and open the radiator fill cap (the cap of the spout where you pour the coolant).

Go underneath the car and find the other radiator’s drain which should be located directly under the radiator fill cap. Open it and use a bucket to catch all the old coolant that pours out of this drain. Consult the owner’s manual if you’re having a hard time finding it.

Step 3: Use a Flush Product

Once the old coolant is out, close the radiator drain and prepare your flush preferred product. Follow the instructions as printed on the product.

Step 4: Drain Again

With the coolant flush in your radiator, you need to flush out any coolant left within the engine itself. To do this, start your engine and let it run for 10 mins or as required by the flush product’s instructions.

After, drain the flush product by repeating step 2.

Step 5: Add New Coolant

Once the engine is cool enough, it’s time to add in your coolant and water mixture which should be in equal parts. Ensure that you fill the radiator full with the mixture to get the most out of the coolant.

After that replace the caps and you should be ready to go!

Bottom Line

And that was the difference between orange and green coolants along with everything else you should know about coolants in general.

Armed with this knowledge, you can ensure your engine has all the care it needs to last you for many more years to come!

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About Matthew Webb

Hi, I am Matthew! I am a dedicated car nerd! During the day, I am a journalist, at night I enjoy working on my 2 project cars. I have been a car nerd all my life, and am excited to share my knowledge with you!

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