By Lukeron Lubricants · Last updated
Quick answer
Coolant colour does not tell you the type. Makers use colours in different ways, so two coolants of one colour can differ and two colours can be alike. Do not mix different coolant types unless the vehicle maker says it is safe, because mixing can reduce protection and cause deposits. Choose by the type or specification in the owner's manual, mix concentrate to the right ratio with clean water, and top up with the same coolant the vehicle already has.
Coolant colour: what it tells you and what to do
| Colour | What it tells you | What to do |
|---|---|---|
| Green | Only the dye. The type depends on the maker. | Check the label and the manual for the type |
| Red | Only the dye. The type depends on the maker. | Check the label and the manual for the type |
| Blue | Only the dye. The type depends on the maker. | Check the label and the manual for the type |
| Pink | Only the dye. The type depends on the maker. | Use the coolant that meets the maker's specification |
General guidance only. Follow the vehicle maker's manual for the coolant type, the ratio and the change interval.
Coolant comes in green, red, blue, pink and other colours, and many vehicle owners wonder which one to buy and whether two colours can be mixed. The short answer is that colour alone does not tell you what is in the bottle. This guide explains what coolant colour means, what it does not mean, and how to choose and top up safely.
What coolant colour really tells you
Coolant is dyed so that you can see it and so that a leak is easy to spot. The dye helps a mechanic recognise the coolant, but makers use colours in different ways. Two coolants of the same colour can be different types, and two coolants of different colours can be the same type. So the colour is not a reliable guide to the chemistry.
Why the type matters more than the colour
Coolant is made to protect the radiator, the water pump and the engine from rust, corrosion and scale, and to stop freezing and boiling. Different coolants use different additive packages to do this, and vehicle makers choose the one that suits their metals and their service interval. That is why the owner's manual names the coolant type or the specification, and not just a colour.
Can you mix red, blue, green and pink coolant?
Do not mix different coolant types unless the maker says it is safe. Mixing different types can reduce the protection and, in some cases, cause sludge or deposits that block the cooling passages. A different colour does not always mean a different type, and the same colour does not always mean the same type, so you cannot decide by looking. Check the coolant label and the manual.
What to check on the label
- The coolant type or specification, which should match the vehicle maker's requirement.
- The mixing ratio: concentrate is mixed with water, for example 1:3, 1:7 or 1:9, parts of coolant to parts of water.
- The vehicle or the engine type the coolant is made for, such as cars and light vehicles or heavy-duty and diesel engines.
- The change interval that the product states, and the one in your manual.
Topping up coolant
- Top up with the same coolant the vehicle already has, mixed to the right ratio.
- Check the level when the engine is cold, in the coolant tank (reservoir).
- Plain water is only a short-term fix to get home. Have the system checked and refilled with the right mix soon after.
- If the level keeps falling, look for a leak.
Changing from one coolant type to another
If you want to change the type, flush the cooling system first so that the old coolant does not mix with the new one. Do this only when the vehicle maker allows the new type. Then fill with the new coolant mixed to the right ratio, using clean water.
Lukeron coolants
Lukeron makes two radiator coolants: an anti-freeze coolant (red and blue) in 1:3, 1:7 and 1:9 dilution, and a glycol coolant (green) concentrate in 1:3 dilution. Both come in 1 litre, 50 litre and 210 litre packs. Choose by what your vehicle or engine maker names, and ask us if you are not sure.
Mistakes to avoid
- Choosing coolant by colour alone.
- Mixing different types because they look alike.
- Using hard water to dilute concentrate. Use clean water, preferably distilled or demineralised.
- Opening the radiator or reservoir cap on a hot engine.
- Topping up again and again with plain water, which weakens the protection.