This article may contain affiliate links. For details, visit our Affiliate Disclosure page.
Choosing the correct type of coolant is important for your car. For some, the decision can be difficult, as there are many types of coolants on the market. In this article, I hope to make things easier for you by giving you the answer to the question: “How do I choose coolant for my car?“.
There are different types of coolants available on the market, but the main ones are:
• Organic Acid Technology (OAT)
• Hybrid Organic Acid Technology (HOAT)
All these coolants are meant to perform the same function – that is, to keep your engine at an optimal temperature and protect it from corrosion. You can check your manual to see what type of coolant is best for your car.
Hybrid Organic Acid Technology (HOAT)
HOAT seems to be the best option among the coolants available. This is because it has several benefits over OAT and mineral-based coolants: it performs better in terms of corrosion protection, has a better long-term performance and high-temperature behavior.
However, HOAT goes through a different process than mineral-based coolants; for one it is more expensive.
If you choose to use HOAT, you should also check the label of your car’s radiator and make sure it specifies a maximum operating temperature of 100 °C (212 °F). The recommended coolant concentration is:
The coolant’s pH level should also be checked during regular maintenance. The proper range is between 5.2 and 6.2. If the pH level is higher, there’s a chance some metal corrosion products may be formed, causing corrosion of the engine parts.
Organic Acid Technology (OAT)
OAT is the most common coolant type on the market. It’s used by several types of cars, including domestic and commercial vehicles and motorcycles.
See More: Which Brand of Coolant Is the Best?
Some people prefer OAT over HOAT because it doesn’t contain metallic salts, which can lead to metal corrosion. This is especially important in case there’s a high level of exhaust gases, as metallic substances such as H2S or CO will quickly corrode HOAT (and also bio-catalyst HOAT).
But there’s no guarantee that OAT doesn’t contain some of these substances. Some HOAT coolants contain up to 30% by mass of H2S, which is used in the production of various chemicals such as sodium sulfite and potassium sulfite.
The pH level should be checked regularly using a pH meter, as with alkaline or acidic coolants.
This type of coolant is the most corrosive of all types available on the market. According to a European survey, among 495 car manufacturers, only 14 use mineral-based coolants in their cars.
In the UK, there are just two manufacturers that use this type of coolant: Ford and Alfa Romeo. These vehicles have to be permanently maintained with this particular type of coolant at all times.
Mineral-based coolants are the least common among the three types. However, they are sometimes used by certain vehicles and motorcycles for different purposes.
With mineral-based coolants, iron or copper ions are used as corrosion inhibitors. This is why this type of coolant can be used both in and out of hibernations despite its high corrosiveness: unlike HOAT coolants, this kind of water does not contain metallic salts that could corrode metal parts.
Mineral-based coolants have the advantage of being cheaper than HOAT. On the other hand, their performance is not as high as that of OAT coolants.