What Coolant For My Car? Find the Right Coolant for Your Car

Not sure what coolant for my car is the right one? You’re not alone. Choosing the wrong coolant can lead to overheating, corrosion, or costly repairs. And with so many types and colours out there, it’s easy to get it wrong.

Using the right coolant keeps your engine protected all year round. But mix the wrong ones, or top up blindly, and you could damage your system without knowing it and cause overheating.

In this guide, you’ll learn exactly how to find the right coolant for your car. From types and colours to safe top-up tips, we’ve got you covered step by step.

What Coolant for My Car is the Right One?

The right coolant for your car depends on the engine type and the manufacturer’s specs. You can’t just use any other coolant. Using the wrong one may damage engine parts or reduce corrosion protection.

Check your vehicle handbook or the label under your bonnet. Most cars in the UK use either OAT (Organic Acid Technology) or HOAT (Hybrid Organic Acid Technology) coolants. Older models may need IAT (Inorganic Acid Technology).

Modern vehicles usually need long-life OAT coolant. It lasts longer and offers better engine protection. However, some brands use their own blend, so follow their recommendation.

When in doubt, ask your mechanic. Always match the right coolant with your car for safety.

What Are the Different Types of Coolant?

Coolants differ by their chemical makeup. Using the wrong one can damage your engine over time. Here’s a quick breakdown of the main types you’ll find in the UK market.

a. IAT (Inorganic Additive Technology)

This coolant is usually green. It contains silicates that protect older engines from corrosion. IAT is commonly used in old and classic cars made before 1998. It needs replacing every two years for full protection.

b. OAT (Organic Acid Technology)

You’ll often find OAT coolant in orange. It uses organic acids instead of silicates. It’s designed for newer vehicles and offers longer protection, up to five years. Don’t mix it with other types.

c. HOAT (Hybrid OAT, Phosphate-Free)
This one is usually turquoise. It’s phosphate- and NAP-free, so it suits some modern European engines. It combines the benefits of both IAT and OAT. Always check compatibility before use.

d. HOAT (Hybrid OAT with Silicates)

This version is often yellow. It blends silicates and organic acids for balanced engine protection. It’s used in various American and European models. Suitable for aluminium parts.

e. Si-OAT (Silicated HOAT)

This type appears purple. It includes both silicates and organic acids. It offers long-lasting protection in high-performance engines. Found in many German vehicles.

f. P-HOAT (Phosphated HOAT)

This coolant is usually blue or pink. It contains phosphates and organic acids. Most Japanese and Korean cars, like Toyota or Hyundai, use it. Check your handbook before topping up.

Each coolant is made for specific engines and climates. Always follow the manufacturer’s guide before making a choice.

Typical Coolant Choices by Car Manufacturer

Different car brands recommend specific coolant types. This is based on engine materials and design.

• BMW, Mercedes-Benz, Audi, VW
  These often use G13 or Si-OAT coolants. Look for pink or purple fluid. They’re phosphate- and silicate-free, suited to modern European engines.
• Ford, Vauxhall, Peugeot, Citroën
  These commonly use OAT-based coolants. Orange or red coolant is typical. Check your manual for confirmation.
• Toyota, Honda, Nissan, Hyundai, Kia
  Asian manufacturers usually prefer P-HOAT coolants. You’ll see pink, blue or sometimes green coolant. They include phosphates for better corrosion protection in aluminium engines.
• Land Rover, Jaguar
  These often use HOAT or Si-OAT coolant types. Colours may vary, so double-check before topping up.

Always go with what your manufacturer recommends. Coolant isn’t one-size-fits-all.

How to Check and Top Up Coolant Safely

Start with a cold engine. Never open the coolant cap while it’s hot. Hot coolant can spray and burn you.

Locate the coolant reservoir. It’s usually a clear plastic tank with a coloured liquid inside. Look for the min and max level markers.

If the coolant is below the minimum line, it needs topping up. Use the correct coolant type for your car. Don’t guess. Check your manual or ask your mechanic.

Unscrew the cap slowly. Pour the coolant until the level is just below the max line. Don’t overfill it.

Secure the cap tightly. Wipe up any spills. Run the engine for a few minutes and recheck the level. If levels drop often, you may have a leak. In that case, speak to a professional.

But if the damage is already done and repairs seem too costly, it may be time to move on. You can sell your damaged car with Exchange My Car. Compare multiple instant offers, get free car collection, and enjoy a fast, hassle-free selling experience.

When Should You Replace Coolant?

Coolant doesn’t last forever. Over time, it breaks down and loses its ability to protect your engine.

Most car makers recommend a coolant change every 2 to 5 years. Some newer models may last longer, but always check your owner’s manual.

Also, replace coolant if it looks rusty, dirty, or oily. These are signs it’s no longer working properly.

If your engine overheats or the warning light comes on, check your coolant. It might be time for a flush and refill.

Regular changes prevent corrosion and help your cooling system last longer. It’s a simple step that protects your engine.

Frequently Asked Questions

Can I mix different coolant colours?

No, mixing different coolant colours is not a good idea. While it might seem harmless, each coolant colour often represents a specific chemical formula, such as IAT, OAT, or HOAT. These formulas are not always compatible with one another.

When mixed, different coolant types can react chemically. This may cause the fluid to gel or thicken, reducing its ability to circulate and regulate temperature. Over time, this can lead to clogged coolant passages, corrosion, or even engine damage.

What colour coolant for my car?

Coolant colour varies based on the chemical composition, not just branding. That’s why it’s not a reliable way to choose what’s right for your car. For example, green often indicates IAT coolant, orange may mean OAT, and blue or pink could signal a HOAT-based coolant. But colours aren’t standardised across all manufacturers.

So, how do you know which one is right? Your best bet is to check your vehicle’s owner’s manual. It will list the specific type or specification required. If you don’t have the manual, speak to a trusted mechanic or visit your car brand’s official website.

What’s the difference between coolant and antifreeze?

Coolant and antifreeze are closely related, but not exactly the same.

Antifreeze is a concentrated liquid, usually made from ethylene glycol. It must be mixed with water before use.

Coolant is the ready-to-use mixture of antifreeze and water (typically 50/50). It regulates engine temperature and prevents freezing or overheating.

So, in short, antifreeze is the raw ingredient, and coolant is the finished product your engine uses.

What happens if coolant is low?

Driving with low coolant can be dangerous for your engine. Coolant is what keeps your engine at the right operating temperature. Without enough of it, your engine may overheat in minutes, especially on warm days or during long drives.

You might notice signs like the temperature gauge rising, steam under the bonnet, or a dashboard warning light. If you ignore it, overheating can damage the cylinder head, cause bubbling in the radiator, or even cause a blown head gasket repairs that are often very expensive.

If you suspect low coolant, stop your vehicle safely and let the engine cool down. Once it’s safe, check the coolant level and top it up with the correct type. Still, it’s vital to inspect for leaks or book a garage visit if the issue repeats.

What should I do if I’ve used the wrong coolant?

If you’ve accidentally poured the wrong type of coolant into your system, don’t panic. A small amount may not do major harm immediately, especially if you catch it early. But it’s important to take action soon to prevent long-term damage.

Different coolant types can react with one another and create deposits or sludge inside your cooling system. This reduces efficiency and protection, and in some cases, may lead to corrosion or part failure.

To fix it, book a coolant flush at a local garage or do it yourself if you’re confident. Refill the system with the manufacturer-approved coolant and monitor your levels going forward. When in doubt, speak with a professional for peace of mind.

In Conclusion: What Coolant for My Car is Right?

Choosing the right coolant for your car isn’t just good maintenance. It protects your engine from serious damage. The wrong type can cause corrosion, poor performance, or even overheating. That’s why it’s important to check your manual, match the correct coolant type, and top it up safely.

If your car’s cooling issues keep coming back, it might be time to rethink repairs. Try our free car value checker to see if selling makes more sense than constant spending.

And if repairs are becoming too frequent or costly, it might be time to sell your car. We buy any car near you, regardless of its age, make, or mileage. 

With Exchange My Car, you can sell any car hassle-free. All our partners offer free collection service and will pay you fast. Sell your car now.

Looking for more practical car care advice? Browse our blogs for expert tips on keeping your car roadworthy and problem-free.