10 Best

Antifreeze Coolants

of June 2023

Proper maintenance of your car is essential. Part of that maintenance includes protecting the engine from freezing during a cold spell or overheating in the summer. Regularly replacing your car’s antifreeze coolant is the solution. It has a much lower freezing temperature and a much higher boiling point than just water.

Adding antifreeze diluted 50%-50% with water will protect your engine from freezing and damage in cold weather conditions. While water alone freezes at 32 ℉, an antifreeze-water mixture has a freezing temperature of around -35 ℉. Antifreeze also helps to keep the engine cool during the hot summer months by preventing your car from overheating. Water boils at 212 ℉, but some brands produce an antifreeze-water mixture that has a boiling point of 375 °F! In addition, antifreeze contains important additives that lubricate the internal workings of your engine and help to prevent corrosion or pitting. This extends the life of your vehicle’s parts in general.

However, there are a lot of antifreeze coolants on the market. It’s important to select the right one for your vehicle. We’ll see that each type of antifreeze coolant is for a specific car model. But there is also antifreeze that is suitable for a wide range of cars. We’ll go through some options, to help you make an informed decision!

How can I find out which antifreeze my car needs?

There are generic types of antifreeze that are good for a variety of vehicles, and types of antifreeze that are specific to your vehicle.

• If you want to find which antifreeze is right for your car, you can consult the owner’s manual (it usually is available online as well, if you don’t have a hard copy).

• Alternatively, you may be able to peek inside your radiator to see which color antifreeze you have presently.

• Also, there may be a sticker near your car’s engine bay telling which antifreeze to use.

• There are also charts that help you decide, depending on your car’s manufacturer.

What can happen if I use the wrong antifreeze?

Using the wrong antifreeze can corrode your radiator and radiator hoses, water pump, and cylinder gaskets. If you don’t flush out the system, it can damage the engine as well. If you happen to use the wrong coolant, you should flush out the system with water, and then fill it with the correct antifreeze.

Why should I mix the antifreeze with water?

You’ll notice that most antifreeze in the Best Reviews Guide list is already premixed, to be 50% water/50% antifreeze. The principal ingredient of antifreeze is ethylene glycol, which has a freezing temperature of 8-11 ℉. But adding water lowers the freezing point temperature even further, all the way down to -34 ℉. The molecules of ethylene glycol mix with water molecules, not allowing them to crystallize into a solid as the temperature drops. So, if you buy antifreeze that isn’t mixed with water, it’s very important to add water yourself!

How often should I replace antifreeze?

Experts recommend replacing the antifreeze once a year. Particular brands will say that they should be changed after traveling a certain number of miles, such as 300,000 miles for the Prestone Antifreeze Coolant.
 

There are a number of types of antifreeze whether a vehicle has a diesel or gasoline engine or based on the manufacturer. Some of the different formulas include

• IAT (Inorganic Additive Technology) coolant: This is a low-silicate formula, that can protect your engine from freezing, boiling, rust, corrosion, or premature water pump failure. An example is the Zerex Original Green Low Silicate Concentrate Antifreeze/coolant.

Zerex Original Green Low Silicate Concentrate Antifreeze/Coolant

• OAT (Organic Acid Technology): This uses organic acids as the ingredient that inhibits freezing or boiling. An example is the General Motors ACDelco DEX-Cool Coolant Antifreeze. It’s suitable for all General Motors vehicles.

General Motors ACDelco DEX-Cool Coolant Antifreeze

• HOAT (Hybrid Organic Acid Technology), or G-05: This formula contains nitrites, to protect diesel engine cylinder liners from cavitation. It contains additives that protect against limescale deposits that might form if you put hard water into your radiator. An example is the Valvoline Zerex G05 Phosphate Free Concentrate Antifreeze/Coolant.

Valvoline Zerex G05 Phosphate Free Concentrate Antifreeze/Coolant

• P-HOAT (Phosphated HOAT): This formula has phosphates added, and is suited for Asian vehicles (Toyota, Nissan, Honda, etc.). The Zerex Asian Vehicle Red Antifreeze/Coolant is specifically for Asian vehicles.

Zerex Asian Vehicle Red Antifreeze/Coolant

 

• Si-OAT (Silicated HOAT): This is formulated for protecting systems that include aluminum, to protect it against corrosion. An example is the Zerex G40 Phosphate and Nitrite Free Concentrate Antifreeze/Coolant. It’s primarily for German-made cars: Volkswagen, Audi, Mercedes-Benz, and Porsche.

Zerex G40 Phosphate and Nitrite Free Concentrate Antifreeze/Coolant

• Multi-vehicle antifreeze/coolant: There are also antifreeze formulas that have special additives to be suitable for all vehicles. An example is the Valvoline Multi-Vehicle 50/50 Prediluted Antifreeze/Coolant. It’s intended to extend the life of higher-mileage vehicles. It protects against cold-weather freeze up, hot weather boil over, rust and corrosion.

Valvoline Multi-Vehicle 50/50 Prediluted Antifreeze/Coolant

 

Based on all the consumer reviews we've scanned, these are the top things they mentioned about the antifreeze they selected:

• Good even in moderate climates: One customer said that he doesn’t have to worry about his engine freezing since he lives in Southern California. Nonetheless, it’s still recommended to use antifreeze, in order to prevent damage to your car’s thermostat, heating coil, and radiator.

• Try to use the original coolant: Besides ethylene glycol, there are other additives to antifreeze to prevent corrosion. It’s important that you use the antifreeze that is specific to your vehicle. Looking into your radiator to see what color it is is not always reliable, since the coolant can change color over time.

Here are some tips from the manufacturers and users, regarding selecting the right antifreeze for your vehicle:

• Extended life coolant: You’ll see that certain antifreeze that is called an “extended life coolant”. This is usually OAT antifreeze, without nitrites, phosphates, or silicates. It’s recommended in systems with aluminum or iron alloy.

• Embittered antifreeze: Antifreeze is highly poisonous, both to animals and humans. You’ll notice that many types of antifreeze have a bittering agent added to them. This is so that domestic animals or wildlife won’t be attracted to the color of the antifreeze and attempt to drink it.

• Properly draining the old antifreeze: To replace the old antifreeze, you have to locate your radiator’s drain plug. Unscrew it, and drain the old antifreeze into an oil pan or bucket only for this purpose (you only have to do this once a year, after all). You then open the radiator cap and pour in either premixed antifreeze or antifreeze that you have to dilute yourself. Close the radiator cap and turn on your engine. This will distribute the antifreeze throughout your engine. You can add a bit more, to ensure that your radiator is full. Close the radiator cap again, and you’re ready to go!

Final Verdict

We went through the various types of antifreeze coolants, and why it’s important to use one that is compatible with your vehicle’s engine. Whether you experience very cold winters, or very hot summers, or just want to keep your engine in proper working order, the right antifreeze coolant is an absolute must!