Can You Mix Different Anti-Freeze & What Types Can You Mix?

Red Blue Green Mix Coolants

Everyone knows that their vehicle uses anti-freeze, but did you know that there are different types of anti-freeze out there? If you’ve found that you purchased a different kind and want to know if you can mix them, you’ve come to the right place.

We’ll break down everything you need to know about the different kinds of anti-freezes here and let you know what will happen if you decide to mix them. Even better if you’re in a pinch, we’ll let you know what you can do. By the end, you’ll be ready to get your car back on the road!

Different Types of Anti-Freeze

While there are tons of different anti-freeze varieties out there, the two main types used for your vehicle are a traditional green anti-freeze and an orange anti-freeze that uses Dexcool. But while the color can be a great starting point to figure out what kind of coolant you have, sometimes the color can be misleading.

For instance, not every vehicle that has orange anti-freeze has Dexcool. And if you add Dexcool into your regular orange anti-freeze, you’re asking for a problem. Always double-check and triple-check which kind of coolant is in your vehicle – don’t just rely on the color.

If you can’t find out for sure what kind of anti-freeze is in your vehicle, it’s best to complete a coolant flush so you know for sure what’s in there.

Always check the specifications of what type of coolant your engine type requires!

Green Coolant

Green Coolant

Green coolant is by far the most common type of anti-freeze in vehicles. Green anti-freeze doesn’t last as long as orange coolant, but you should double-check your vehicle’s recommended service intervals before heading to flush out the coolant every few thousand miles.

That’s because modern vehicles are getting better and better and sealing their cooling systems, which allows the fluid to last longer between changes. So, before you go flushing your system, take a peek in the owner’s guide and see what it says!

Remember that these intervals are for the manufacturer-recommended anti-freeze, so if you’re using something else, you can expect that the service intervals will change as well.

Orange Coolant

Fill Coolant

Orange coolant is often a product named Dexcool. GM manufactured Dexcool and promised that you’d only need to flush your system every 150,000-miles if you used it. This is a much longer service life than regular anti-freeze, so you can see why its popularity surged.

The only problem is that Dexcool didn’t always work as advertised. Moreover, just because you open the hood and see orange coolant, that doesn’t mean you have Dexcool. Always double-check what kind of coolant is in your vehicle instead of relying solely on the color.

If you’ve never flushed the coolant on your vehicle, you can check the owner’s manual, if you have changed the coolant, you might be out of luck. If you don’t know, go ahead and flush the entire system before potentially mixing the wrong type of coolant.

Less Common Types

Fill Coolant

While green and orange anti-freeze products are by far the most common, you can also find vehicles that use a pink, blue, or gold anti-freeze. This largely comes down to your vehicle’s manufacturer and what kind of coolant they decided to put in the vehicle.

The differences between these coolants vary, but it almost always comes down to the types of additives used in each anti-freeze. They are all glycol-based, but the additives that they use make a big difference.

If you can’t find the exact coolant that your vehicle uses, stop by the dealership or flush the entire system before adding the new coolant. Keep in mind that adding a different kind of coolant to a vehicle under warranty can void the warranty.

What Happens if You Mix Different Types of Anti-Freeze?

Since there are so many different anti-freeze types, the exact results of mixing anti-freeze will vary depending on what anti-freezes you mix – but the short answer is that you should never mix different types of anti-freeze.

For instance, if you mix green and orange anti-freeze, the two different types of additives will mix and coagulate. In short, they’ll get thick and gum up the system. Not only does this shorten the lifespan of the coolant, but it can cause your engine to overheat and damage your system.

So, while there are some forums out there that claim you just need to go to the shorter lifespan of the two coolants – this is 100 percent false, and it can severely damage your engine. Don’t risk it, and don’t mix different types of coolants.

Keep in mind we’re talking about types of coolant here – not brands. Most times, the brands simply switch the names but use the same formulas, so as long as they’re the same type, you’re still in great shape.

What if You’re in a Pinch?

Engine Overheating

If you’re stuck out in the middle of nowhere and need to top off your coolant to get where you’re going, you have better options than mixing the wrong types of anti-freeze. While mixing the anti-freeze might get you where you’re going without any problems, you’re taking a risk.

Instead, all you need to do is add some distilled water to top off your system. While diluting the system with more water lowers the boiling point and raises the freezing point, a system with only 10 percent anti-freeze and 90 percent water will still only have a freezing point of 26 degrees Fahrenheit.

So, as long as you’re not driving during a snowstorm, you should be alright. If you read that and thought – I want the lowest possible freezing point, so I’m going to add 100 anti-freeze and no water – you’re mistaken. Adding water actually lowers the freezing point and glycol – to a point. The ideal anti-freeze to water ratio is 60 percent anti-freeze and 40 percent water.

But if you’re in a pinch, add water – not a different kind of anti-freeze. Not only will you avoid problems, but you’ll have no problem getting where you’re going either.

Final Thoughts On Mixing Anti-Freeze

If you’re thinking about mixing anti-freeze to save a few bucks – don’t. While you might save $20 to $40 now, it can easily cost you a couple hundred to a couple thousand dollars down the road.

If you’re worried and trying to save a little money, just add distilled water to the system. Distilled water is not the same as tap water – as tap water has chemicals that can lead to corrosion inside your cooling system.

But distilled water is cheap – you can usually find it for as little as $1 per gallon. Don’t take the risk by mixing anti-freeze types, it’s just not worth it.

Written by: Magnus Sellén

Founder, owner & main author of Mechanic Base. I have been repairing cars for more than 10 years, specialized in advanced diagnostics & troubleshooting. I have also been a drifting driver and mechanic for over 7 years.