Antifreeze is an important part of any internal combustion engine for a couple of reasons. First, as the name implies, it's meant to prevent freezing. If you were just using water in your coolant system it would be inefficient because it would boil off too quickly, but it would also freeze too easily in the winter. When water freezes, it has a tendency to cause the pipes to burst which would happen in your engine as well. For that reason, antifreeze and water mixed together are able to prevent anything from freezing solid inside your engine when it gets too cold outside.
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The flip side of that coin is that, in addition to being known as antifreeze it's also known as coolant because it's necessary for cooling your engine down. As we said, water would boil off if you were just using that to try to cool your engine down because of the extreme temperatures. However, mixed with antifreeze the boiling temperature is drastically increased so it's able to prevent your engine from overheating.
For a long time, the only antifreeze that was available was the green kind which is something called ethylene glycol. If you've ever noticed a particularly sweet smell when you're pouring coolant into the tank, or when you have a leak, that's what's causing it. Ethylene glycol is even illegally added to wine sometimes to sweeten the batch and cut costs. Animals are also highly attracted to the smell and will drink it if given the chance which could prove fatal because it's highly toxic.
In the 1990s General Motors introduced an orange kind of coolant that they refer to as Dexcool. This orange coolant is probably the second most common kind of coolant on the market and the big difference between ethylene glycol and Dexcool is how long they last. Dexcool is supposed to last in your system for about 5 years or 150,000 miles of driving. On the other hand, the green ethylene glycol coolant should probably be changed every 30,000 miles.
Your best bet for knowing when to change your coolant is to check your owner's manual however because some manufacturers have drastically different recommendations. For instance, for some Mercedes Benz models it’s 120,000 miles to 150,000 miles as well. On the other hand, Hyundai says do the first change after 60,000 miles, and then every 30,000 miles thereafter.
Since the advent of Dexcool there have been numerous other colours of antifreeze that have hit the market. It can get confusing if you're not sure what the difference is. Let's take a look at what can happen if you accidentally mix different coloured antifreezes in your engine, and what they even mean in the first place.
What Happens if You Use the Wrong Colour Antifreeze?
The different colours of antifreeze are formulated in different ways to include different ingredients that are meant to not only cool down your engine and prevent freezing, but they also have additives that help reduce corrosion and foaming. When you mix different colours of antifreeze, you're mixing a number of chemicals that may not be meant to go together. The labels will let you know if what you're using is the same formulation as what you have in your vehicle already, but if you're not familiar with what these labels mean and you're not sure what's in your radiator already then that may not be helpful at all. The fact is not all of us are the kind of vehicle owners who pay that close attention to the things we put in our cars, even if we want to be on top of this kind of stuff all the time. It's easy to overlook stuff sometimes, or forget, and it's also difficult to make the time to learn this information sometimes as well.
Luckily, it's not too difficult to figure out the best way to keep your radiator running smoothly and your vehicle from overheating with just a little bit of information, planning, and preparation as it relates to your coolant.
If you mix orange and green antifreeze, which are the two most common colours, what you're going to create in your radiator is a jelly-like sludge. When these two interact they thicken, and that will seriously hinder your vehicle's ability to properly cool down as a result. This jelly mixture will clog up the lines and it will require a full flush to get it cleaned out.
There are many other colours of antifreeze available as well, and some of them may say they are compatible with things like Dexcool and the original green antifreeze, but your best bet for the sake of safety and for the sake of your wallet is to stick with only using the exact same kind of coolant that is already in your radiator unless you're going to do a full flush to clean it out. It's just not worth it if you end up causing damage to your vehicle as a result.
What Do the Different Colors of Antifreeze Mean?
We've covered a little bit about green antifreeze and orange antifreeze, but there is a veritable rainbow available. You'll notice that some kinds of antifreezes are labelled as organic acid technology, abbreviated as OAT, as well as hybrid organic acid technology or HOAT, which have additives that are meant to reduce corrosion and extend their life. With that in mind, let's take a look at what the different colours are and why there's a difference in the first place.
Orange Antifreeze: As we mentioned, Dexcool is the most well-known kind of orange antifreeze out there but it's actually not the only one. There is a kind of orange antifreeze designed by OEM that is specifically formulated to be used in Chrysler, Jeep, and Dodge vehicles. It will not be labelled Dexcool so that's how you'll know the difference.
On the subject of Dexcool, it should also be noted that there are some issues with this coolant. Drivers have complained that if they let Dexcool levels get too low that there can be excessive corrosion in their radiator and throughout the engine as a result. For years there have been complaints about Dexcool having issues and even though GM has tried to address some of them, they do tend to persist. It's not something that every driver who uses Dexcool complains of, but it is something to be aware of just in case.
Blue Antifreeze: Most often when you see blue antifreeze it has been specifically formulated for use in vehicles manufactured by Nissan, Infiniti, Mitsubishi, and Mazda. This is an anti-corrosion, long life formula that's meant to last about five years without needing to be changed.
Blue Antifreeze II: There's also a second blue antifreeze available that is a slightly different shade of blue. This one has been formulated for Subaru, Acura, and Honda vehicles.
Yellow Antifreeze: This formulation is meant to work with vehicles manufactured by Hyundai and Kia. It's also an extended life blend that should be good for 5 years worth of driving.
Pink Antifreeze: This antifreeze blend is meant for Japanese vehicles produced by Lexus, Toyota, and Scion.
Euro Pink Antifreeze: Not to be confused with the previous kind of pink antifreeze, this brand is marketed by OEM and it is specifically called Euro antifreeze on the label. The bottle is purple which makes it a little confusing. This kind is designed for use in Volkswagen, Porsche, and Audi vehicles.
Gold Antifreeze: If you drive a Ford, Mercury, or Lincoln vehicle then gold antifreeze has been formulated to specifically work with your vehicle's cooling system.
Euro Gold Antifreeze: Just like there is a Euro pink antifreeze there is a Euro gold antifreeze as well. This one is designed for a wide range of European models including those made by Volvo, Mercedes-Benz, BMW, Jaguar, Mini, and Smart car.
All of these specialized blends of coolant are best used in the car as they are recommended for, but they're also not necessary for your particular model of vehicle. There are also other brands out there that use these same colors but not specifically for the vehicles mentioned. If you drive a Ford, you don't have to use gold antifreeze by any means. The green antifreeze that you're used to will absolutely work just as well and will probably cost quite a bit less. Just remember, as we said, do not mix the colours if you want to switch from one to the other. Always do a full flush first before you add any new coolant to the system just to be safe.
Can the Wrong Coolant Cause Overheating?
It's not impossible that using the wrong kind of coolant could end up causing your car to overheat over time. To start with, if you're using a blend of traditional green antifreeze and water it should be a 50/50 mix. However, if you have your ratio off too badly then you could end up having an overheated engine. Water is good at cooling, but it does boil at a very low temperature. If your coolant mix is too much water, that's going to boil off and leave your engine susceptible to overheating.
As we've seen with the detailed list of different colour antifreezes, these are specifically formulated for certain vehicles. The formulas are designed to work with the cooling systems of these vehicles to maximize their lifespan and reduce corrosion based on how the engines have been designed for different manufacturers. If you end up using the wrong kind of coolant, maybe you're using coolant that was designed for a Subaru in your Camaro, then it's possible that it's not going to work exactly the way you intended it to and it may end up causing more corrosion than your specific model can take which will cause your engine to overheat far sooner than you would think.
What Color is Universal Antifreeze?
Green antifreeze is the universal formula that nearly any vehicle can run on. Even though this is a universal formula, that doesn't mean it's safe to mix with other colours though. It just means that any vehicle should be able to run perfectly fine when you have green antifreeze in it as long as the system has been cleared out already and there is no residue of any different colour antifreeze in the lines.
Some kinds of antifreeze will not work in every vehicle, and some as we have seen are designed by specific auto manufacturers for specific vehicles. However, the green antifreeze should get the job done in every single car on the road.
The Bottom Line
Coolant has become one of those unnecessarily complicated things for some drivers in recent history. Back when there was only green antifreeze it was pretty easy to know what to do, right? All the different colours and formulations can now make it somewhat overwhelming and confusing at the best of times which is especially stressful if you are a new driver and you don't have a lot of experience with how to maintain an automobile and how everything is supposed to work.
As we said, the best bet if you want to ensure that your engine is going to work exactly the way you want it to is to never mix antifreeze colours. Once you are more familiar with how your car works, and the different formulations of antifreeze, then you may be comfortable switching from one to another once you've determined that the formulation is the same kind of antifreeze; it just has a slightly different colour. It's not always guaranteed that you're going to damage your vehicle by mixing colours but if you're not sure what you're doing then you never want to take the risk.
With that in mind, until you know that one formulation is chemically the same as another formulation, keep the same colour in your coolant tank at all times until you get it properly flushed by a mechanic to ensure that you don't end up creating that gel-like substance and having to risk and to damage as a result.