What Is HOAT Coolant? Learn Its Functions

Engines are the most complex part of a car and it generates massive heat. It is the coolant that keeps the heat in control and saves the engine from an explosion. There are several coolants in the market, and you must learn about their variants before choosing the ideal one for the car. One such type is HOAT coolant.

What Does HOAT Stand For?

HOAT stands for Hybrid OAT or Hybrid Organic Acid Technology. This coolant is a mixture of IAT (Inorganic Acid Technology) and OAT (Organic Acid Technology) coolants.

Typically, its color is dyed yellow, but it also comes in turquoise, pink, blue or purple colors. This coolant contains added silicates that offer additional protection against corrosion and rusting on the aluminum components of the vehicle.

This best serves new cars, while many European and Asian vehicle manufacturers, including Ford and Chrysler, recommend HOAT coolant for their vehicle models. You must flush out this coolant from the car’s system after five years or every 150,000 miles.

hoat vs oat
HOAT and OAT coolants. (Source: JK-Forum)

How Does the HOAT Coolant Function?

Like every other type of coolant, the prime function of HOAT is to cool the car engine. While doing so, it goes through metal passageways. Hence, it has to deal with different operating temperatures.

Due to hybrid-engineered chemical composition, HOAT antifreeze stops the rust from building up. It functions with equal efficiency at very high and low temperatures, and therefore it can serve for more than five years. This coolant does not need regular changing like IAT. It may also not be as long-lasting as OAT, but it does provide better protection against rust.

While using HOAT, you need to mix additives into the system as the engine manufacturer suggested or after every 25k miles. To stop being frozen, it uses both silicates and organic acids.

Since the HOAT coolant is not compatible with OAT/IAT coolants, do not mix these two. Mixing multiple coolants will not ensure enhanced performance. Instead, it cancels the benefits of one variant.


HOAT vs OAT: The Differences

There are several points on which the Hybrid OAT coolant differs from the OAT variant. The most evident difference is their color. While OAT is purple, HOAT comes in Orange.

The second difference in these is their lifetime. While the ideal runtime of HOAT is five years and 1000K miles, OAT lasts for ten years and 150K miles.

Another significant factor that distinguishes these two coolants is the price. OAT coolant costs much higher than the HOAT. Usually, one gallon of OAT will cost you $50-$60.

If there is no urgency, purchase from online stores that offer it at a cheaper rate. But beware of the dealers who sell this coolant at a low price. There is a chance that they are not selling an authentic product.


HOAT coolant helps to keep the engine cool in all types of temperatures. However, always take the suggestion of the car manufacturer or an experienced technician before choosing a coolant.