Engine coolant in vehicles should be checked at least twice a year. Ideally, this should happen just before the two extreme seasons of summer and winter and a top up should be added if necessary. However, as a maintenance product, coolant is often neglected, and vehicle owners don’t always have a solid supply in stock.
As you only use a little at a time, over the years, you might find that you have multiple containers with a little coolant left in each, but they differ in type and brand. Rather than buy a fresh container, you might be tempted to mix coolants and use up what you have left, but is this a good practice? Below, we’ll take a closer look at engine coolants and what impact mixing can have.
Defining engine coolant
Engine coolant is a specific fluid that is designed to circulate through an engine and ensure it stays at the correct temperature. Typically, coolants are made up of around 50 per cent water and 50 per cent propylene or ethylene glycol. Coolant products also include small quantities of additives that can offer protection. Engine coolants are usually coloured, but exactly which colour they feature can vary. Blue, orange, green, and pink coolants can all be found.
The job of coolant is to lower the engine temperature and ensure it stays consistent. Automotive vehicles generate intense heat, and over extended service, this heat can damage and even destroy and engine when it isn’t controlled. With coolant added, the engine can continue to work at optimum regardless of temperature.
Understanding coolant types
Different types of vehicles have different engines and as a result, require different kinds of coolants. As a result, leading manufacturers formulate specific fluids for each that ensure protection and performance for specific makes and models.
Common engine coolants include Inorganic Additive Technology, or IAT for short, “OAT” Organic Acid Technology and Hybrid Organic Acid Technology, also referred to as HOAT. Phosphate HOAT, Phosphate-Free HOAT and Silicate HOAT are also available.
To make sure that you use the correct coolant for your vehicle, always consult your vehicle owner’s manual or your original equipment manufacturer (OEM).
Can you select coolant based on colour?
Once engine coolants were colour-coded, so colour played a role when picking products. Each coolant type was coloured specifically to indicate its application, compatibility, and properties. Today, this isn’t so. Coolants come in different colours still, but manufacturers choose them to differentiate products within their range and which are selected vary between brands. As a result, colour alone is no way to tell if the coolant in your car is identical to product in a half-empty container.
What can happen if you mix coolants?
On the topic of mixing different coloured coolants, you’ll come across two polarised opinions. Some people see no issue with the practice providing that the type of coolant in the system is the same as the type you wish to top up with. However, coolant experts, advise that you should not mix different coloured coolants for safety reasons.
For example, combinations exist that can cause extensive damage to cars Mixing an OAT coolant with an IAT coolant can be extremely detrimental. When mixed OAT coolant and IAT coolant react turning the engine coolant into a type of gel that can block the cooling system. When this occurs, the engine will overheat. To remove this sticky paste can take considerable flushing and can even inflict expensive damage to your car’s system. The same scenario can happen when organic acid and propylene glycol-based coolants are mixed.
Combining various types of coolants in your system can have extensive and costly consequences. When a mix solidifies and clogs your engine it results in overheating, but this is just the beginning of your problems. The excessive heat can degrade cylinder heads, break head gaskets, ruin hoses, corrode your water pump and radiator and reduce your car’s overall performance, increasing running costs.
Resulting in both short and long-term harm to your investment, the best option for both you and your vehicle is to avoid the practice of mixing engine coolants.
When they’re looking to cut costs or save time, people don’t always consider the ultimate and unwanted consequences of coolant mixing. However, when your aim is to save expense the approach of mixing coolants without well-considered investigation and research is unwise. A small and simple mistake can end up costing you considerably. As for saving time by avoiding finding out the correct product to use for your engine and procuring some, you will find that you lose even more of your operating hours when your car is off the road for expensive repair work.
Ensure you only use the correct coolant for your engine type and stick to the best practice of never mixing engine coolants.