Taking care of your car requires more than filling it with gas and changing flat tires. Tons of moving parts and fluids work in unison to get your vehicle from point A to B safely. One key component to getting your car moving is coolant. Knowing the basics of what coolant is and the different types available will help you find the right coolant for your vehicle.
What Is Engine Coolant?
Engine coolant is crucial to helping your car run smoothly. In the summer, your car’s engine can get extremely hot. Coolant raises the boiling point of the cooling system to prevent the engine from overheating. In the winter, coolant lowers the freezing point so that the fluids inside the engine don’t freeze up.
In other words, without coolant to regulate the engine temperature, your engine can reach extreme temperatures and potentially damage your vehicle. If left unchecked, this damage can become irreversible, resulting in expensive repairs.
How Long Does Coolant Last?
Unfortunately, simply throwing coolant into your engine reservoir once won’t solve all your problems. It doesn’t last forever. Because of all the active ingredients in it, coolant will eventually break down and become less effective at protecting your engine. Old coolant can also produce rust and sludge, which can further damage the cooling system.
Are Coolant and Antifreeze the Same?
The terms are often used interchangeably, and it’s understandable why: they’re almost synonyms but not quite. Antifreeze is coolant before it’s been diluted with water.
So, when you finally find the right coolant for your vehicle, follow the instructions on the bottle, no matter what the label says (antifreeze or coolant). It may say to dilute the solution in the bottle with water, even though the label says you’ve just bought coolant.
Types of Car Coolant and Their Ingredients
Different coolants will have varying contents, but there are a few main ingredients that should be in any blend. These include water, ethylene glycol or propylene glycol, and corrosion inhibitors.
Three main types of coolants are currently available: inorganic additive technology, organic acid technology, and hybrid organic technology.
Inorganic Additive Technology (IAT)
IAT dominated the coolant market for many years. Today, however, it’s pretty uncommon because it’s meant for older cars and depletes relatively quickly compared to its modern competitors. It’ll typically need a change every two years and is mainly used in vehicles made in the United States before 1998. You can often spot IAT by its distinctive green colour.
Organic Acid Technology (OAT)
OAT coolant is designed for cars made after 1998. It usually needs to be changed every five years, but some blends claim to last up to ten years. Most OAT coolants are orange, but you can also find them in red, yellow, and purple. Cars made by General Motors, Saab, and Volkswagen will typically require OAT coolant.
Hybrid Organic Acid Technology (HOAT)
HOAT combines the benefits of IAT and OAT and has many subcategories. Different vehicles will require particular HOAT coolants. Below is a list of some vehicles compatible with each HOAT type:
- Regular HOAT
- Ford, Chrysler, and European manufacturers
- Phosphate-free HOAT
- BMW, Volvo, Tesla, Mini
- Phosphated HOAT
- Toyota, Nissan, Honda, Hyundai, Kia, and other Asian manufacturers
- Silicated HOAT
- Mercedes-Benz, Audi, Volkswagen, Porsche
For best results, you’ll need to change HOAT coolant at least every five years.
Do not mix different coolant types in the same vehicle. They’re not compatible with each other, and mixing can accelerate corrosion and cause severe damage to the cooling system.
Finding the Right Engine Coolant
With so many choices, it can be difficult to pick the right coolant for your vehicle. If you use the wrong coolant, your vehicle may not run properly.
For example, phosphated HOAT is usually recommended for vehicles manufactured in Asia because of heat transfer issues in those vehicles. It uses carboxylates and phosphates instead of silicates to inhibit corrosion in the engine. Silicated HOAT, on the other hand, contains silicates and is free of phosphates, which react to the minerals in hard water in Europe and cause corrosion. So, European models often require this type of HOAT.
To make the right choice, you’ll need to know where your vehicle was made along with its type, make, model, and age.
As with many maintenance tasks, the owner’s manual for your car will provide you with further information on choosing the right coolant for it and how often to change it. If you don’t have a physical copy of your manual, you can likely still find all the information you need online by looking up your car’s details.
Other Coolant Tips
When looking for and using coolant, keep these tips in mind:
- Some coolants can be put straight into your engine coolant reservoir and be good to go. Others need to be combined with water in a 50/50 ratio.
- Colour alone cannot be used to identify coolant. Different types may be the same colour, so read all the labels carefully to make sure you know what you’re buying.
- Even if a coolant claims to last more than five years, it’s better to change it earlier than to leave it until it’s too late. If your coolant starts to look rusty, it’s time for a change.
- When it’s time to replace your coolant, wear proper protective equipment and dispose of the old liquid safely at a recycling or disposal centre.
As with any automotive product, read the full directions on the coolant type you select to make sure you use it properly. You can also check out online forums where car owners with the same vehicle may have reviewed different products, including coolants.
If you need more advice on picking the right coolant, stop by your local NAPA Auto Parts store to speak with an expert.