Repair instructions
What Kinds of Antifreeze and Coolant Are There?
Summary
- Antifreeze adjusts the coolant’s boiling and freezing points to protect your engine.
- Engine coolant is a mixture of antifreeze and water.
- There are three main types of car coolant: Inorganic Additive Technology (IAT), Organic Acid Technology (OAT), and Hybrid Organic Acid Technology (HOAT).
- Pink antifreeze often uses either OAT or Phosphate Hybrid Organic Acid Technology (PHOAT).
- Always refer to your vehicle’s owner’s manual for the recommended antifreeze or coolant.
How Does Antifreeze Function in Your Vehicle?
Antifreeze is a critical component in your car’s cooling system, ensuring the engine operates efficiently even under extreme conditions. When mixed with water, it forms coolant, which circulates through the engine and radiator to absorb excess heat. This process helps prevent engine overheating by moving the heat away from critical engine parts.
Antifreeze works by raising the coolant’s boiling point to prevent the radiator fluid from boiling over and causing engine overheating. Additionally, it lowers the freezing point of the coolant, allowing the system to continue functioning even in sub-zero temperatures.
Antifreeze vs. Coolant: What’s the Difference?
While the terms antifreeze and coolant are often used interchangeably, there’s a distinction between them. Coolant is the final mixture of antifreeze and water, designed to regulate your engine’s temperature. Antifreeze alone isn’t sufficient to cool your engine—it needs to be diluted with water to form the proper coolant mixture.
Types of Car Coolant
The type of antifreeze you use will determine the type of coolant your vehicle gets, and different formulations are designed for various engine types and operating conditions.
1. Inorganic Additive Technology (IAT)
IAT coolant contains inorganic additives like silicates, phosphates, and borates to protect against corrosion, particularly in older engines made of iron and steel. However, this type of coolant breaks down faster than others, requiring more frequent changes, typically every two years or around 24,000 miles.
IAT coolant is typically green and is best suited for older vehicles that use more traditional materials.
2. Organic Acid Technology (OAT)
OAT coolant uses organic acids instead of inorganic additives, making it ideal for newer engines, especially those with aluminum components. OAT coolants are more durable and resistant to corrosion, lasting longer than IAT coolants. Common colors for OAT coolants are orange, yellow, red, and purple.
This type of coolant is designed to last for about 5 years or up to 50,000 miles.
3. Hybrid Organic Acid Technology (HOAT)
HOAT coolant blends the benefits of both IAT and OAT formulations. It’s highly effective at reducing corrosion and is designed to last longer, typically requiring changes only every five years or 50,000 miles. HOAT coolants are commonly orange or yellow, and like OAT, they’re best suited for modern aluminum engines.
How to Mix Antifreeze and Water to Create Coolant
When making your own coolant, it’s important to follow the right mixing ratios. Pure antifreeze freezes at around 0 to -5°F, while water freezes at 32°F. However, when combined, the mixture can handle much colder temperatures—coolant typically freezes at anywhere from -35°F to -84°F, depending on the mix ratio.
The ideal mixture for most climates is a 50/50 blend of antifreeze and distilled water, which offers balanced freezing and boiling protection. In colder climates, you may opt for a 60/40 or 70/30 mixture for better freeze protection.
Always use distilled water to mix with antifreeze to avoid impurities that could affect the coolant’s performance.
Frequently Asked Questions
What Type of Antifreeze is Pink?
Pink antifreeze typically uses Organic Acid Technology (OAT) or Phosphate Hybrid Organic Acid Technology (PHOAT). Many modern vehicles, including Toyota, use pink coolant due to its effectiveness in protecting engines with aluminum components.
Does It Matter Which Antifreeze You Use?
Yes, it’s essential to use the correct antifreeze for your vehicle. Consult your owner’s manual to find the recommended coolant type and color. Using the wrong coolant could damage your engine or affect its cooling performance.
How Often Should Antifreeze and Coolant Be Changed?
It’s generally recommended to replace your vehicle’s coolant every two years or around 24,000 miles, depending on the coolant type. For OAT and HOAT coolants, you may go longer—up to five years or 50,000 miles. Regular coolant changes are essential to preventing overheating, freezing, and long-term engine damage.
Keep your engine running smoothly by staying on top of your coolant maintenance. Regular changes not only protect your engine but also save you money by preventing costly repairs.
