What Coolant Should I Use in My Car

Choosing the right coolant is about more than just picking a coloured liquid off the shelf. It’s paramount, and its purpose is to protect your engine from overheating, freezing, and corrosion and using the wrong type can cause real damage. 

What Are Antifreeze and Radiator Coolant

Antifreeze and radiator coolant are closely related. Antifreeze is the undiluted glycol-based concentrate, while coolant is the final product, usually a 50/50 mix of antifreeze and distilled water. When used together, they regulate engine temperature and prevent internal corrosion. You should never use plain water for long, as it lacks essential additives that protect the system.

What Is Type 2 Coolant?

Type 2 coolant is a long-life, pre-diluted antifreeze formulation that is commonly used across Japanese car makes like Honda or Toyota. It’s designed to last for five years or 95,000 kms and contains no silicates or borates, which makes it gentler on engine components.

While it sounds generic, “Type 2” refers to a specific OEM coolant type so always check your car’s manual or ask us at Mt Roskill.

How to Identify the Right Coolant for Your Car

Not all coolants are compatible with all car engines. There are 3 types of coolants:

• Inorganic Additive Technology (IAT): Often green, for older vehicles.
• Organic Acid Technology (OAT): Commonly orange or red, found in many modern cars.
• Hybrid Organic Acid Technology (HOAT): Usually yellow or blue, mixing IAT and OAT properties.

Modern vehicles often need brand-specific coolant, like Toyota Super Long Life or Ford Motorcraft Orange. Using the wrong type can lead to rust, clogged radiators, or potential water pump damage.

How to Put Coolant in the Radiator

Here are the key steps:

1. Let the engine cool completely.
2. Open the coolant reservoir—not the radiator cap if the engine is hot.
3. Add coolant slowly until it reaches the “Full” or “Max” mark.
4. Start the engine and let it run to help circulate the fluid and release air pockets.
5. Re-check the level and top up if necessary.

If your radiator itself needs topping up, that should only be done when the engine is cold and under professional guidance, especially if the system needs bleeding.

How Full Should My Coolant Reservoir Be?

The coolant reservoir should sit between the MIN and MAX lines when the engine is cold. If it’s too low and evaporates quickly, that could indicate a leak= Too high may lead to overflow and pressure issues.

Our mechanics check reservoir levels as part of every routine service—because accurate coolant levels are crucial for engine health.

How Often Should I Change My Coolant?

Coolant doesn’t last forever—even long-life varieties break down over time. This is the general rule:

• Traditional coolant: change every 40,000 to 50,000 km.
• Extended life coolants: 80,000 to 100,000 km.

If you’re unsure about how often you need to change your coolant, we recommend referring to your owner’s manual or better yet, book a coolant flush and inspection with us. It’s an easy and quick way to prevent potential damage from leaks and ensure that your vehicle is in shape.

Your coolant system is vital to your engine’s performance and longevity. Whether it’s choosing the right type, topping up safely, or fixing leaks, we are here to help.

If your coolant disappears unusually quickly, looks discoloured, or your engine is running too hot, don’t wait for things to get worse. Get it checked by our mechanics.