Engine coolant, also known as antifreeze, is an essential component of your car’s engine. Without it, the engine can overheat and cause lasting damage to your vehicle. It’s important therefore to keep it topped up, but the coolant required will differ depending on the model of your vehicle.
In the following guide, we break down the different types of antifreeze and what to consider when deciding what coolant your car needs. You can also learn what exactly engine coolant is in our detailed analysis and see which coolants we have available to order online.
Types Of Engine Coolant
There are several types of coolant to choose from, organised by chemical composition and colour:
- IAT (Inorganic Additive Technology) – green
- OAT (Organic Acid Technology) – orange
- HOAT (Hybrid OAT) – yellow
- HOAT phosphate free – turquoise
- P – HOAT (phosphated HOAT) – pink or blue
- Si – OAT (Silicated HOAT) – purple
Which Coolant Should I Use?
Our part picker can help you select coolants specifically for your car via its registration number. However, when determining the correct coolant for your car, you should always consult the vehicle’s manual, as adding incompatible coolant can cause damage to the engine.
Each type of coolant has a recommended model it is compatible with:
- Older model cars (pre 1998) – green IAT
- General Motors, Saab & Volkswagen – orange OAT
- Ford, Chrysler & other European models – yellow HOAT
- BMW, Volvo, Tesla, & Mini – turquoise HOAT phosphate free
- Toyota, Nissan, Honda, Hyundai, KIA & other Asian models – pink or blue P HOAT
- Mercedes-Benz, Audi & Porsche – purple Si OAT
The label of the coolant should always be checked alongside your car manual, as some colours can look different e.g., a yellow tint may actually be orange OAT coolant.
Engine coolant is not the only fluid in your vehicle you need to maintain. To learn how to check the transmission fluid, check out our guide and keep your car’s parts working efficiently.
