Coolant is one of the most critical automotive fluids. It plays an important role in making sure that your car’s engine cooling system is working well. The coolant reduces wear and tear, corrosion thereby checking the damage to the engine block. The automotive coolants come in a range of colours. We can find them in say, purple, blue, green, yellow or orange in the market.

Read: 10 Most Googled Questions On Car Coolant

All coolants might not be compatible with all cars. The anti-freeze mixture you use would vary with the car you drive. It would also depend on when and where your car was made. While picking the right coolant, check with the manual and try to get the one the automaker recommends for your model. If in doubt you can always make use of a service centre.

Here are the 3 different kinds of engine coolant-

  1. Inorganic Additive Technology (IAT)

    Prevent engine overhrating
    Green Coolant

    This coolant comes in a green colour. But nowadays, it won’t be a surprise if you encounter a blue IAT. Inorganic Additive Technology coolant demands more frequent changing compared to modern coolants. You might need a coolant change every two years or so. Along with ethylene glycol, they also use silicates in the manufacturing process of IAT coolant. The silicates deter corrosion.

    If there is any such thing as an across-the-board coolant, it would be this one. This is because we can use this coolant on just about any vehicle. Besides, it is relatively more affordable as well!

    Why not buy Green Coolant from GoMechanic at ₹119 only? We’ll make sure you get the best at the best price as well! 

  2. Organic Acid Technology (OAT)

    While IAT coolants are made with ethylene glycol, OAT coolants on the other hand use propylene glycol. And another point of distinction between the two is that while IAT is mostly used in earlier models, OAT is suited for the current ones. OAT coolants only need to be flushed in around every 5 years. Because of this, they are Extended Life Coolants (ELC).

    OAT coolants are usually orange. But in rare cases, we might come across a deep green OAT coolant (Honda manufactures dark green OAT coolant). OAT coolants might even come in red, pink, yellow or purple colours.

    As the name suggests Organic Acid Technology coolants are made using organic acids. It is devoid of any phosphates and silicates. GM’s DexCool is an OAT coolant.

  3. Hybrid Organic Acid Technology (HOAT)

    In the olden days, HOAT used to be the yellow coolant. But now things have changed and we can find HOAT in a spectrum of colour from blue to orange. Phosphate-free HOAT can come in turquoise. The anti-corrosive properties of HOAT can be credited to silicates and organic acids present in them. Thus, we can say that HOAT is a mix of OAT and IAT formulation.

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    With Hybrid Organic Acid Technology coolants, you can go an extended period of time without a complete coolant change. Just like OAT coolants, you can use HOAT for 5 years or more. However, if you are looking to buy HOAT coolant make it a point to read the label. Don’t glance at the colour and decide that it is the one for you.

    We can further classify HOAT as follows-

  • Phosphated HOAT (P-HOAT)

    Pink Coolant

    This coolant comes in pink or blue colour. Phosphated HOAT uses phosphates along with organic acids to prevent corrosion. This coolant is compatible with the models from carmakers like Hyundai, KIA and Honda.

  • Silicated HOAT (Si-OAT)

    If you see a purple coolant somewhere, you know you are probably looking at silicated HOAT. Along with organic acids, this coolant uses silicate instead of phosphate to protect the car engine from corrosion. This coolant is compatible with cars from premium auto manufacturers like Mercedes, Porsche and Audi.

Bear these in mind

Water instead of Coolant | Common Car Maintenance Mistakes

  • Just because two cars are from the same brand it doesn’t mean they both use the same coolant.
  • It is generally advised not to mix two coolants together. However, you can go ahead if the brand you use says it’s okay to do so with their product.
  • All yellow coolants are not HOAT. Neither are all orange coolants OAT. The take away is this; don’t judge a coolant by its hue. Read the label.
  • Coolants from some manufacturers need to be diluted. But not others. So, we’ll reiterate; read the label.
  • Periodic vehicle maintenance, servicing and coolant change can do wonders to your car

You should choose the coolant that is compatible with your car. Remember that hybrid cars and EVs do not have a conventional cooling system. Therefore, only use the coolants that are recommended by the carmaker – particularly- in these vehicles.


Gone are the days you can tell the composition of the coolant by its colour. You should not let colour be the only basis for choosing the anti-freeze mixture you want to use. Check out the description on side of the container the coolant comes from. We have said it a million times and we’ll say it again; read the label!

You can purchase Golden Cruiser’s Coolant Red. We’ll deliver them to your doorsteps no matter where you live in the country! Download the GoMechanic Spares App for more. 

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Read: Engine Oil Grades Explained | Know Your Car Engine Oil


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