Choosing the Right Coolant for Your Vehicle

Last updated: 30-01-2024 | By: Sebastian Szlasa

Understanding Coolant and Its Importance

Coolant is essential for maintaining your car's engine temperature, particularly as we approach warmer months. It's a liquid used in the radiator to keep engines cool. Given the trend towards smaller, more powerful cars, effective coolant is more important than ever. In cold climates, the risk of radiator damage increases as water can freeze, expand, and cause cracks when the engine is idle.

Why Not Just Use Tap Water?

While tap water might seem like a convenient emergency substitute, it's not a suitable long-term replacement for coolant. Water alone can lead to corrosion in the radiator, head gasket, and thermostat. Moreover, water's boiling point (100°C) and freezing point (0°C) are not ideal for engine temperature ranges. In extreme heat, water boils, creating pressure and potential overheating, while in cold, it can freeze and damage the radiator.

Coolant Composition

Coolant, typically a mix of Ethylene Glycol, protective additives, and demineralised water, manages engine temperatures above 100°C without boiling and below 0°C without freezing. Glycol isn't as effective at absorbing heat as water, but it modifies water's boiling and freezing points.

Choosing the Right Coolant Type

When selecting a coolant, start with your vehicle manufacturer's recommendations. There are two primary types:

• Type A Coolant: Contains anti-freeze and anti-boil elements like ethylene glycol, lowering the freezing point and raising the boiling point.
• Type B Coolant: More of a rust or corrosion inhibitor with fewer additives, commonly used in pre-1980s vehicles.

So what's the difference between coolant colours? Coolant colours (red, green, blue, yellow, or orange) indicate different formulations:

• Green Coolant: A widely used Ethylene Glycol-based conventional coolant.
• Red Coolant: Suited for aluminium radiators, based on Organic Acid Technology.
• Blue Coolant: Similar to red but Borate-free, designed for modern Japanese vehicles.
• Yellow/Orange Coolants: Universal products representing the latest in coolant technology.

What to do if coolant is low?

If your coolant is low you might ask "can I mix different coolants?" Mixing different coolants is not advised. If your coolant is low, use water only for emergency top-ups.

Regular Coolant Checks

Have your coolant tested regularly by a professional technician, and follow the manufacturer's guidelines for checking the coolant level in the reservoir. Avoid overfilling to prevent system overflow.

Final Thoughts

As the warmer seasons of spring and summer approach, it's wise to consider the last time your car's coolant was replaced. If it's been a while, or if you've noticed your car's temp gauge indicating higher than usual temperatures, it's time to get your coolant checked. Regular maintenance and coolant replacement are crucial for ensuring your engine's health and performance during hot weather. Check with your mechanic to help with this, as they can offer professional guidance and services to keep your engine running smoothly and efficiently throughout the warmer months.

Sebastian Szlasa is an automotive writer for motorfind.com.au, with an extensive background in the automotive and finance industry. Seb is based in Adelaide, Australia. Links: Trademate, Linkedin & Twitter/X.com.