Did you know that different cars require different types of coolant? While it might sound complicated, choosing the right coolant or antifreeze is actually quite straightforward once you know what to look for.
Coolant plays a vital role in keeping your engine at the correct operating temperature. Without it, your engine could overheat in summer or freeze in winter, potentially causing serious and expensive damage.
For more helpful car ownership guides and maintenance advice, visit our maintenance guidance hub.
What’s the Difference Between Coolant and Antifreeze?
Coolant and antifreeze are essentially the same product, just used in different forms.
Antifreeze is a concentrated liquid, usually based on glycol, designed to prevent engine fluids from freezing and overheating. When mixed with water, it becomes coolant.
Coolant is typically a 50/50 mixture of antifreeze and water, helping to regulate engine temperature by:
- Preventing freezing in cold weather
- Raising the boiling point in hot conditions
- Protecting engine components from corrosion
Without the correct coolant, your engine can overheat and suffer long-term damage.
What Type of Coolant Does My Car Need?
The correct coolant for your vehicle will always be specified in your owner’s manual or manufacturer guidance.
Coolants are generally categorised by chemical type and colour, including:
- IAT (Inorganic Additive Technology) – Green
- OAT (Organic Acid Technology) – Orange
- HOAT (Hybrid OAT) – Yellow / Turquoise
- Si-OAT (Silicated HOAT) – Purple
- P-HOAT (Phosphated HOAT) – Blue / Pink
It is essential to use the correct specification for your vehicle. Using the wrong type can reduce protection and potentially cause damage to the cooling system.
How Do You Check Your Engine Coolant?
It’s recommended to check your coolant level at least twice a year—ideally before summer and winter.
To check your coolant:
- Ensure the engine is completely cool
- Locate the coolant reservoir (refer to your handbook if needed)
- Check that the fluid level sits between the MIN and MAX markers
- Top up if necessary using the correct coolant type
Never open the coolant cap when the engine is hot, as the system may be pressurised.
If you’re maintaining your vehicle yourself, it’s also worth understanding what different dashboard warning lights mean. Our guide on Car Dashboard Warning Lights Explained can help you quickly identify potential issues before they become serious.
What Happens If Your Coolant Is Low?
Low coolant can lead to engine overheating, which is one of the most serious issues a driver can face.
Most modern cars have a warning light or sensor that alerts you when coolant levels drop below a safe threshold.
If this warning appears:
- Pull over safely as soon as possible
- Allow the engine to cool
- Check coolant levels
- Top up if required or seek professional assistance
Ignoring low coolant levels can result in major engine damage.
How to Flush the Cooling System
Flushing the cooling system removes old coolant and contaminants that can affect performance.
In general, the process involves:
- Allowing the engine to cool fully
- Draining old coolant from the system
- Refilling with water and a flushing solution
- Running the engine briefly
- Draining again and refilling with fresh coolant
Always follow manufacturer guidance, as procedures can vary by vehicle.
When Should You Replace Coolant?
Coolant does not need replacing frequently, but it should still be checked and replaced according to manufacturer recommendations.
In many cases, this may be every 30,000 miles or more, depending on the vehicle.
You should consider replacing coolant if you notice:
- Discolouration
- Rust or debris
- Poor engine temperature regulation
Always use the correct specification recommended for your vehicle.
Keeping your car properly maintained helps improve reliability and resale value. If you’re thinking about upgrading your vehicle, our guide on How to Sell Your Car Online is a great next step.
Final Thoughts
Choosing the correct coolant is essential for protecting your engine and ensuring long-term reliability.
By checking levels regularly and using the correct specification for your vehicle, you can help prevent overheating, freezing, and costly mechanical damage.
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