When refilling your automobile coolant system, you might have seen that antifreeze comes in several types of color: red, yellow, green, orange, blue, etc. Combining 2 different-colored coolants is common to save a few bucks or clear out the prior ones before restocking. In this case, one question comes to mind: can you mix red and green coolant?
Inorganic Additive Technology (IAT) is used in green coolants. On the other hand, red coolants use Organic Acid Technology (OAT). Since they are made of different technology and formulas, combining them should be prohibited.
Let’s figure out the answers to car owners’ other common questions about automotive antifreeze or coolants.
What are the Uses of Red and Green Coolants?
Green and red coolants have specific chemical balances and are used in certain engines. Learn more about their uses by reading this section intently.
Red coolant is categorized as OAT antifreeze. It is less efficient than IAT coolant in fighting against corrosion. But changing intervals of red coolant is extremely long. It lasts roughly 5 years or 50,000 miles between changes. In fact, red coolant is well-known for its excellent stability.
Like all other antifreeze or coolant types, it also protects the coolant system from degradation and damage. One of the biggest advantages of red coolant is its long-lasting performance.
Remember that antifreeze color is not a determining factor in knowing what kind it is. Manufacturers formulate certain antifreeze types and give them a standard color.
However, most OAT coolants are red. They are also available in yellow and orange color.
It is recommended to check the coolant bottle label before buying instead of looking at the color. From the container label, you will know that it is actually the correct coolant type for your vehicle.
Green coolant is formulated with Inorganic Additive Technology (IAT) and the oldest antifreeze types still available on the market. If you own a classic or older car built before 2000, green antifreeze will be the best choice. Similar to all other coolant types, it also has benefits and drawbacks.
Corrosion is a common problem for car cooling systems. Green coolant fights corrosion and prevents corrosion from the components pretty efficiently. It means the IAT or green coolant types help prolong the cooling system’s lifespan.
But the additives used in IAT coolants break quickly. For this reason, they don’t remain effective for many days. You will need to change the green coolant every 30,000 miles or 3 years. Green coolant is less stable than its counterparts.
Can You Mix Red and Green Coolant?
The short answer is NO. Red and green coolants are differently formulated.
The cooling system of vehicles has a fluid named coolant or antifreeze. This liquid circulates through the transmission and engine. But when 2 incompatible coolants are mixed, the liquid stops delivering its best performance.
Red-green coolant mixture puts pressure on different components of the cooling system. Moreover, the blend impairs corrosion protection.
For this reason, blending the different coolant types is dangerous during an emergency. If you mistakenly mix and use them in your car, damage or crack will appear in the radiator hoses, water pump, and head gasket.
Reasons Why You Can’t Mix Red and Green Coolant
It would be best if you didn’t mix red and green coolants. The reason is they have different formulas for multiple chemicals. Every car’s cooling system runs at specific freezing and boiling points.
Colors usually identify coolants or antifreeze, but this is not a good practice at all. The same types of coolants can be different in color.
In addition, green coolant uses older technology, and classic cars prefer this formula. Since this coolant is ideal for older cars and doesn’t feature modern technology, green antifreeze will not provide the same protection as red coolant offers to new cars.
As a result, modern car owners don’t use IAT coolants and prefer red coolants that use improved OAT technology.
All in all, green antifreeze may become obsolete when more people buy modern cars. Thus, the demand for IAT coolants will decrease. Besides, improved technology in red coolant increases the use of OAT antifreeze.
So, coolants can’t be judged by their color. Two coolants can be mixed only if they have the same compound in the formula and are designed with the same technology.
Mixing incompatible coolants will create a mess in the cooling system. The freezing and boiling points will fluctuate a lot in different circumstances.
More dangerously, the cooling point will be incorrect during winter due to the red-green mixture. As a result, a crack will appear in the cooling lines. Finally, your car will show difficulty starting.
Dangers of Mixing Red and Green
Below are some dangers of mixing red and green coolants. Read them carefully.
Shortens Coolant Lifespan
The organic acid is used to produce red coolant, and it features a longer life expectancy. On the other hand, the inorganic additives formula makes green coolant. This coolant is particularly for older vehicles and has a shorter lifespan.
When these 2 coolants are combined, the additives may react. Thus, the life expectancy of both antifreeze will be reduced.
Disrupting Coolant System
Undesirable chemical interactions will severely ruin the cooling system components functioning characteristics.
Moreover, different sedimentary components will form in the materials due to chemical reactions. The cooling system will get clogged, which will decrease the overall performance of your vehicle.
Simultaneously, your car engine will become less durable and efficient over time.
Damaging the Cylinder Gasket
Red-green coolant mixture will damage the cylinder gasket dangerously.
The prime responsibility of the cylinder gasket is to ensure proper sealing during the compression phase. It helps avoid leaking air-fuel mixture inside the combustion cavity.
In short terms, the cylinder is sealed by a gasket for optimum pressure.
Additionally, green-red coolant creates a strong acid effect. This way, the cylinder gasket wears down quickly, causing a coolant leak.
Clogging the Water Pump
Prolonged use of a red and green coolant blend will cause leaky cooling in the car’s water pump.
The vehicle’s water pump distributes coolant to the engine, preventing overheating. But due to the mixture of incompatible elements, this coolant distributing function gets interrupted. As a result, your car will overheat.
A higher motor temperature is not a good sign at all. It increases the chance of severe damage. Consequently, broken engine parts or piston destruction can happen.
Decreasing the Coolant’s Performance
By mixing the red and green coolants, you are basically decreasing the antifreeze’s performance.
Anti-corrosion chemicals are different in different coolants. So, when mixed, a new additive gets generated that can’t provide the required protection from corrosion and rust.
What to do If You Mix Incompatible Coolants?
Avoid worrying if you mix red and green coolant. Follow the below consideration to deal with the situation.
- Flush the Incompatible Coolant Mixture Out
The first thing you will need to do is to flush out the incompatible coolant. Call a professional mechanic who can help you.
- Replace the Coolant
Add compatible antifreeze to your car coolant system. Make sure to check the manufacturer manual to learn which coolant to use. Avoid overfilling to prevent spilling. Pour the antifreeze at an even level. You will find a minimum and maximum indicator on the exterior.
- Check Coolant Concentration Regularly
Check the coolant level regularly. Let me be clear if you are wondering what the perfect level for coolant is. The coolant amount should be near or right at the maximum line. If the level is lower than this, I suggest you refill it with compatible antifreeze.
What Coolant can You Mix with Red?
Red coolant is OAT (Organic Acid Technology) type. The colors of the OAT coolants are mostly red and yellow. But other colors are also available depending on the manufacturer and the variant. Other colors are dark green and blue.
As mentioned, coolants can’t be classified by colors, and different coolant mixing is possible if they are the same type. So, it is important to know the antifreeze formula or technology before mixing with other coolants.
What Coolant can You Mix with Green?
Green coolant is used in all vehicles till the early 90s and domestic cars from Chrysler, GM and Ford. But sometimes, you may want to save dollars by mixing different-colored coolants.
Learn the coolant formula first. Also, remember that coolants can be combined when they are the same type.
Green antifreeze is made with Inorganic Additive technology. Mix green coolant with other antifreeze that uses the same IAT formula.
The information about whether you can mix red and green coolant will reach you in time before you decide to combine them.
Every car owner wants to keep their engine in tip-top condition. They don’t want to experience a problem related to the car engine as the repair cost is exceptionally high. So, it is incredibly vital to know how coolant works. If you want to avoid engine issues, follow the recommendations.