Is Green, Pink, or Orange Coolant Better? Understanding Antifreeze for Your Car

When you look at your car's coolant reservoir, you'll see a brightly colored liquid—it could be green, pink, orange, blue, or even yellow. This has led to a common and potentially very damaging misconception: that all coolants are basically the same and can be mixed. This is absolutely not true. The color of your coolant is a code for its chemical composition, and using the wrong type can cause serious damage to your engine. Let's demystify the world of antifreeze.

What Does Coolant (Antifreeze) Do?

Coolant is a mixture of antifreeze (typically ethylene glycol) and purified water. Its primary job is to absorb heat from the engine and dissipate it through the radiator. It's called antifreeze because it also prevents the water in the cooling system from freezing in cold climates. But equally important is its third job: corrosion prevention. The additive package in the coolant is designed to protect the various metals inside your engine and cooling system (like aluminum, iron, and copper) from rusting and corroding.

The Different Types of Coolant Technology

The key difference between the colors lies in the type of corrosion inhibitors they use. There are three main technologies:

1. Inorganic Acid Technology (IAT) - Usually Bright Green

This is the traditional, old-school coolant. It uses silicates and phosphates as its primary corrosion inhibitors. IAT coolants work well but have a much shorter lifespan because these inhibitors get depleted relatively quickly. This type of coolant typically needs to be flushed and replaced every 2 years or 50,000 kilometers.

2. Organic Acid Technology (OAT) - Often Orange, Red, or Dark Green

OAT coolants are the 'long-life' variety found in many modern cars. They use organic acids as corrosion inhibitors, which do not deplete as quickly. This allows them to provide protection for much longer, often up to 5 years or 1,50,000 kilometers. They are specifically designed for modern engines that use more aluminum components.

3. Hybrid Organic Acid Technology (HOAT) - Typically Yellow, Pink, or Turquoise

As the name suggests, HOAT is a hybrid that combines the benefits of both IAT and OAT. It uses organic acids but adds a small amount of silicates to provide a faster-acting protective layer. This provides excellent long-life protection and is used by many European and some American car manufacturers.

Why You Should NEVER Mix Coolant Types

The chemical compositions of these different coolants are not compatible. Mixing an IAT (green) with an OAT (orange) coolant can cause a chemical reaction. This can lead to the coolant 'gelling' or thickening, turning into a sludge-like substance that can clog the narrow passages in your radiator, heater core, and engine block. This will cause your engine to overheat and can lead to thousands of rupees in damage. The corrosion inhibitors can also cancel each other out, leaving your engine unprotected.

The Golden Rule: Use What Your Manufacturer Recommends

The color is just a dye and not a universal standard. A GM orange is different from a Toyota pink. The only way to know the correct coolant for your car is to check your owner's manual or consult a professional. Never top up your coolant with a different color or type. If you're low on coolant and unsure what type to use, it's safest to top up with distilled water in an emergency and then have the system professionally flushed and refilled with the correct coolant.

Using the right coolant is critical for your engine's long-term health. If your coolant is old, discolored, or you suspect the wrong type has been added, a professional flush is the best solution. Book a cooling system service with Drvyn to ensure your car has the right protection.