Advice
Which engine coolant should I use for my car?
Here’s how to choose the right engine coolant for your car, plus how to safely top up and check coolant levels in this guide.
Words by: Nimisha Jain
Published on 1 November 2025 | 0 min read
What is engine coolant?
Engine coolant is a mixture of water and antifreeze. It helps maintain the temperature of the car to keep the car running safely.
When you drive your car and the engine heats up, some of the heat is lost through the exhaust while the rest is absorbed by the coolant to keep the car cool and functioning. As part of the fluid is anti-freeze, an engine coolant also prevents the engine and its components from freezing or cracking in winters. Overall, the function of the engine coolant is to protect the rubbers, plastics, and metals that are found in the engine by preventing corrosion, over-heating and freezing. An overheated engine can lead to some expensive repairs such as head gasket replacement or even engine replacement, which is why it’s important to check and top-up your engine coolant regularly.
When you drive your car and the engine heats up, some of the heat is lost through the exhaust while the rest is absorbed by the coolant to keep the car cool and functioning. As part of the fluid is anti-freeze, an engine coolant also prevents the engine and its components from freezing or cracking in winters. Overall, the function of the engine coolant is to protect the rubbers, plastics, and metals that are found in the engine by preventing corrosion, over-heating and freezing. An overheated engine can lead to some expensive repairs such as head gasket replacement or even engine replacement, which is why it’s important to check and top-up your engine coolant regularly.
Which engine coolant should I use for my car?
You should only use an engine coolant that’s compatible with your car as there are different types of coolants available in the market and using the wrong one can damage your engine.
You should check the car’s manual to find out which engine coolant is recommended by the manufacturer. If you’ve misplaced the car’s manual, you can also ask a professional for help. There are also various online tools that can help you find the right coolant for you.
You should check the car’s manual to find out which engine coolant is recommended by the manufacturer. If you’ve misplaced the car’s manual, you can also ask a professional for help. There are also various online tools that can help you find the right coolant for you.
How to top up engine coolant?
Once you’ve found the right coolant for your car, follow these steps to top-up the engine coolant:
1. First and foremost, ensure that the engine is cool is before you access it. 2. Next, check if the coolant needs to be diluted or not. Some coolant come as a ready mixed while the others are concentrates. 3. Once the coolant is ready to be poured, locate the coolant reservoir – if you can’t find it, refer to your car’s manual. 4. Loosen the reservoir cap a little to release the pressure before you open it completely. Start pouring the coolant - the reservoir will have a line indicating the level it needs to be filled to. Stop pouring just before you reach the line to avoid spillage. 5. Finally, screw the cap back on and you’re ready to go. Most modern cars have a sealed cooling system, so they don't require frequent topping up unless there’s a leak. If you notice any leaks while topping up the engine coolant, you should get it inspected by a professional before driving your car again. Remember, you should handle the coolant with care as it contains chemicals. In case of any spills, wipe off the coolant immediately.
1. First and foremost, ensure that the engine is cool is before you access it. 2. Next, check if the coolant needs to be diluted or not. Some coolant come as a ready mixed while the others are concentrates. 3. Once the coolant is ready to be poured, locate the coolant reservoir – if you can’t find it, refer to your car’s manual. 4. Loosen the reservoir cap a little to release the pressure before you open it completely. Start pouring the coolant - the reservoir will have a line indicating the level it needs to be filled to. Stop pouring just before you reach the line to avoid spillage. 5. Finally, screw the cap back on and you’re ready to go. Most modern cars have a sealed cooling system, so they don't require frequent topping up unless there’s a leak. If you notice any leaks while topping up the engine coolant, you should get it inspected by a professional before driving your car again. Remember, you should handle the coolant with care as it contains chemicals. In case of any spills, wipe off the coolant immediately.
How to check the level of engine coolant?
You can check the coolant reservoir to find out how much engine coolant is left in your car. The coolant reservoir is translucent and has marks indicating the full and empty levels so you can see how much fluid is left inside. Remember, you should wait for the engine to fully cool down before checking the reservoir.
Where can I buy engine coolant?
You can usually buy engine coolants online or in-person at auto parts shops, general stores such as B&Q or Tesco, or at petrol stations.
How long does engine coolants last?
Different engine coolants last for a varied period of time.
An Inorganic Acid Technology (IAT) usually needs changing every two to three years, however this type of coolant is less commonly used nowadays. The rest of the coolant types typically need changing every five years. This includes: • Organic Acid Technology (OAT) – this is the most common coolant used in newer cars • Hybrid Organic Acid Technology (HOAT) • Phosphated Organic Acid Technology (POAT) • Silicated Organic Acid Technology (Si-OAT) You should consult your car’s manual and adhere to their coolant recommendations. You should also read the instructions on the product that you use.
An Inorganic Acid Technology (IAT) usually needs changing every two to three years, however this type of coolant is less commonly used nowadays. The rest of the coolant types typically need changing every five years. This includes: • Organic Acid Technology (OAT) – this is the most common coolant used in newer cars • Hybrid Organic Acid Technology (HOAT) • Phosphated Organic Acid Technology (POAT) • Silicated Organic Acid Technology (Si-OAT) You should consult your car’s manual and adhere to their coolant recommendations. You should also read the instructions on the product that you use.
Are engine coolant and radiator fluid the same?
Yes, radiator fluid is another name for engine coolant.
Is engine coolant the same thing as antifreeze?
No, engine coolant and anti-freeze are different. Antifreeze is a concentrated product that help protect your car in the heat and cold weather.
When anti-freeze is mixed with water, the diluted product becomes engine coolant.
When anti-freeze is mixed with water, the diluted product becomes engine coolant.
Can engine coolant evaporate?
No, an engine coolant doesn’t evaporate as it’s in a sealed system. If the coolant levels drop dramatically, there may be a leak in the engine reservoir. It’s best to consult a professional and fix the issue before your drive again.
Keep reading: Car service plans: are they worth it?
Keep reading: Car service plans: are they worth it?