Any responsible car owner wants to keep their vehicle running smoothly and efficiently for as long as possible. That means you need to do general maintenance on your vehicle. You'll go in to get your schedule oil change, you'll rotate your tires, you'll top up your washer fluid. Part of this also includes making sure that you have enough antifreeze in your car. The last thing you want is for your engine to overheat. But how do you know what kind of antifreeze you need to use? And is it safe to mix one kind with another?
Most of us are familiar with two kinds of antifreeze. There is green antifreeze and orange antifreeze. Or at least that's how it used to be. These days you can actually get yellow antifreeze, blue antifreeze, pink antifreeze and more. The fact is, mixing these liquids is not safe. If you run low on antifreeze, you can't just pour any old bottle of stuff you find at Walmart. If it's not the same as what was already in your vehicle, you're risking damage to your car by putting something new in without cleaning out the old.
So why are there so many kinds and what is the difference? Let's take a look.
What is Antifreeze?
As the name suggests, antifreeze is meant to control the temperature of your engine. Paradoxically, it is also called coolant, which would imply the opposite effects of what the word antifreeze means, but the terms are generally used interchangeably because it does perform both functions in your vehicle. Technically speaking, coolant and antifreeze are not always the same thing. You can buy coolant that is not antifreeze and comes in a premixed formulation that you can add directly to your radiator. But, as we said, oftentimes people use either term to refer to the same thing.
Antifreeze is a chemical that is usually made up of something called ethylene glycol and is mixed 50/50 with water in your radiator to circulate through your engine and maintain an optimal temperature. When you mix antifreeze with water it becomes coolant. But in the same way that chocolate syrup needs to be mixed with milk before it becomes chocolate milk, antifreeze is not coolant until you mix it with water.
Point is, when you use antifreeze or coolant you are regulating the temperature of your engine. It stops things from freezing up in the winter and also stops things from overheating after extended use in extremely hot temperatures.
Antifreeze and coolant also have a secondary effect, which is to add lubrication to prevent corrosion from your engine and radiator.
Why Does Antifreeze Come in Different Colors?
The different colors of antifreeze exist for a clear reason once you understand the chemical makeup and purpose of them. Unfortunately, it's not always clear to everyone why these things come in different colours and what it even means.
Green Antifreeze: Green antifreeze is what most people are used to when they think of antifreeze. It has an almost neon green shade to it and a sweet smell. This is the ethylene glycol that is the basis of most antifreeze is in coolants. It's also one of the easiest to identify substances, and it leaks from your vehicle, because nothing else is the same striking shade of green.
Green antifreeze is actually something you need to keep an eye on because it could potentially be very dangerous. That sweet smell is very attractive to animals. Curiously enough, there is a history of cats in particular getting sick and dying because they found a puddle of spilled antifreeze and tried to drink it. If this does happen, to a pet or a person as some children have also fallen prey to drinking green antifreeze because the color is so enticing, it can be fixed by administering alcohol like vodka. The ethanol in alcohol counteracts the effects of ethylene glycol. That's just something to keep in mind in case of an emergency, as even a couple of teaspoons of antifreeze could be lethal to a small pet.
Orange Antifreeze: The second most common kind of antifreeze that you'll find on the market is orange in color. Orange antifreeze is often something called Dexcool. It is also an ethylene glycol based chemical, but there are additives in it that cause it to turn orange. These attitudes are what make it an extended life kind of antifreeze. That means it will last longer in your vehicle without needing to be changed, and it has enhanced anti-corrosion properties to allow that to happen. Other than the fact that is intended to last longer in your vehicle than green antifreeze, there's not much difference.
It's worth noting that there have been issues with cars that run exclusively on the orange Dexcool coolant. GM created Dexcool as an alternative to traditional antifreeze back in the 1990s. Though it technically lasts for much longer in your system of the green does, when it's allowed to run too low there have been cases in which vehicles have shown excessive acid buildup in corrosion as a result. Just something to be aware of.
OEM has designed a kind of antifreeze that is also orange which is specifically formulated just for Chrysler, Jeep, Dodge vehicles.
There are a number of other antifreezes that are now available on the market that further confuse the issue. There's a veritable rainbow of antifreeze colors, and each one is meant to work with specific kinds of vehicles. These are generally made with something called organic acid technology, often abbreviated as OAT or hybrid organic acid technology abbreviated as HOAT. They are meant to reduce corrosion which causes them to last longer.
Pink Antifreeze: Pink antifreeze is specifically targeted at a handful of Japanese automakers and their vehicles. Toyota, Scion, and Lexus are all specified as the vehicles you should be using with something like an extended life pink antifreeze.
Euro Pink Antifreeze: OEM markets something called Euro antifreeze that is also a pink, though it is sold in a purple bottle. This is meant for Audi, Volkswagen, and Porsche vehicles.
Yellow Antifreeze: Like pink antifreeze, yellow antifreeze has been specifically formulated for a couple of vehicle manufacturers. In this case, Hyundai and Kia are the recommended recipients of yellow antifreeze. Also, like pink, this is an extended life antifreeze which means it's going to last you for about five years worth of driving.
Blue Antifreeze: Blue antifreeze has been formulated for use in Infiniti, Nissan, Mazda, and Mitsubishi Vehicles. It's another long life, anti-corrosion formula meant to last a good five years in your radiator. There are other blue antifreezes that are for use in Acura, Honda, and Subaru vehicles. The color blue on the label is slightly different for these than in the one meant for Nissan and Mazda.
Gold Antifreeze: Gold antifreeze has been formulated to work in Ford, Lincoln, and Mercury vehicles.
Euro Gold Antifreeze: There's another kind of gold antifreeze that is designed for an array of European vehicles including BMW, Jaguar, Mini, Smart, Volvo, and Mercedes-Benz.
What Happens When You Mix Antifreeze Colors?
Green antifreeze and orange antifreeze are the two most common versions that you're going to find on the market. Those other colors are specialized formulations, and most drivers will probably not need to worry about them. Green or orange should work in the cooling system of just about any vehicle on the market, so you don't need to worry about whether or not you have a brand that was specifically made for your car.
The problem with green and orange antifreeze is that they do not work together. They were designed to function in different ways. Orange antifreeze is a long-life antifreeze. It has a different chemical makeup than green, and they cannot be used interchangeably unless you have flushed your cooling system ahead of time.
If you find your system running low on antifreeze, let's say that you have green but it needs to be topped off about halfway, if you were to try to add orange to the system you would actually create a kind of gel. The anti-corrosion chemicals that have been added to the orange mixture to make it last longer, will react when you add it to orange antifreeze. The whole mixture thickens up into a jelly substance.
When your coolant thickens up like this it's not able to circulate properly and do its job. This can lead to your engine overheating, which in turn can leave you with a pretty expensive repair bill overall.
The only thing that coolant needs to be mixed with in your radiator is water. Ironically, antifreeze is much more effective when you mix it properly in the 50/50 proportions with water. Even though it seems like perhaps they would have better temperature regulating properties if you used it undiluted, that's not the case. The freezing point of antifreeze is not that much lower than water by itself, and it is extremely inefficient at protecting your car from overheating if you just use it in its natural state without diluting it. The water and antifreeze mix creates a better temperature control and chemical compound that either one is able to manage just on its own.
How to Flush Your Coolant System
If you're going to switch from a green antifreeze to orange antifreeze, for instance, you need to flush your system to make sure it's clean. Anytime you're replacing the coolant it's a good idea to do a flush of the system just to get any debris and contaminated coolant out of the system entirely. If your coolant has been sitting for too long it could actually have become fairly polluted and dirty in the system, so it's a good idea to make sure everything is flushed clean.
If you've never flushed your coolant system on your own before, it's not that complicated a process. If you're comfortable at all doing DIY car repairs, this would not be too much of an issue to do on your own. Still, if you're not 100% familiar with how to do it, you're in luck that the internet is so helpful these days.
Not only can you find a number of walkthroughs that will guide you step-by-step through the process of how to drain the coolant from your system and clean it out to safely refill with new coolant, there are a number of videos that show you in great detail what you can do.
It's much easier to follow along with a video like this one so you can see firsthand what needs to be done in order to flush your coolant system out. As you can see, it's a fairly simple process and the upside of a video is that you can refer back to it as often as you need to make sure you don't miss any steps to get everything done quickly and efficiently.
Once you have the whole system safely flushed and cleaned, you're free to replace your coolant with any new kind of coolant that works with your car. What you always want to do is check with your owner's manual to make sure you're not using something that should be avoided with your particular kind of vehicle. As we stated earlier, there are a number of different coolants that have come to the market in a veritable rainbow of colours. Many of those are specifically formulated for a certain kind of vehicle. There's no need to buy a blue antifreeze if your vehicle isn't designed to take that kind of substance.
Additionally, even if you do have a car that supposedly would benefit from a pink or a gold antifreeze, there's no reason why traditional green antifreeze wouldn't work just as well for you. Those other colour antifreezes are likely going to cost more money, so it's up to you whether or not you want to use them.
A final note, it's worth remembering that many mechanics and car owners have had problems with the orange Dexcool antifreeze in the past. Dexcool can be given nicknames like Dexkill because of the problems that it's caused. Make sure you're informed and be cautious about anything that you use in your vehicle.