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Inorganic Acid Technology (IAT)
IAT antifreeze, often recognized as the traditional green coolant, was the go-to solution for older vehicles. It contains silicates and phosphates, which serve to protect the
cooling system from corrosion, particularly in engine blocks and other components made from cast iron.
However, IAT has significant limitations, especially as more modern engines use aluminum and rubber components. Silicates can cause scaling in systems with aluminum parts, while phosphates can dry out and damage rubber seals over time.
IAT antifreeze generally requires replacement after 36,000 miles and can break down to the point of causing corrosion and electrolysis, leading to internal damage.
Organic Acid Technology (OAT)
OAT antifreeze emerged in response to the limitations of IAT, particularly for vehicles with aluminum parts and rubber seals. This type of coolant, introduced in the American market by GM in 1994 with Dexcool Orange, boasts a significantly longer service life, typically around 150,000 miles or five to seven years.
OAT antifreeze is free of silicates and phosphates, reducing the risks of scaling and seal corrosion. Various manufacturers have customized OAT formulations, offering coolants like Subaru Blue, Toyota Red, and VW/Audi’s G12 Purple. These colors serve as visual identifiers, helping vehicle owners ensure they are using the
correct coolant for their specific vehicle.
Hybrid Organic Acid Technology (HOAT)
HOAT antifreeze combines the benefits of both IAT and OAT. It includes organic acids for corrosion protection but also incorporates some silicates to offer better protection for aluminum components.
HOAT is commonly used in vehicles from manufacturers like Ford and Chrysler and is typically available in colors like yellow or orange. Like OAT, HOAT antifreeze has a long service life, generally lasting around 150,000 miles, and offers excellent protection for modern engines with mixed metal components.
What Are “All Makes” Coolants?
So what exactly are the “all makes” coolants? They are HOAT – Hybrid Organic Acid Technology. This is an Antifreeze where manufacturers use Nitrates to literally make a “tweener” antifreeze – that’s something in between IAT and OAT – meaning, it’s a jack of all trades, and a master of none. It works, and is a great alternative in a pinch, but there are better methods and options for the customer if their vehicle requires a specific antifreeze – like the Pentosin and Peak manufacturer-specific antifreezes on the market. Mixing traditional IAT (green) antifreeze with an OAT antifreeze can also cause a world of problems. In the late 90’s, Dexcool, GM’s new OAT Antifreeze suffered this wrath and for a while, garnered a horrible reputation because unknowing customers were mixing traditional green IAT antifreeze into their Dexcool systems, eventually creating a brown nasty sludge over time that many consumers faulted Dexcool for. Dexcool was not the problem.
Why Using Manufacturer-Specific Coolant Matters
When choosing antifreeze, manufacturer-specific coolants and “all makes” options differ significantly in how they protect your engine. Manufacturer-specific coolants, like Subaru Blue or VW/Audi G12, are formulated to meet the precise needs of a particular make, offering excellent corrosion protection, thermal stability, and longer service life. These coolants are designed to prevent issues like scaling in aluminum components and seal degradation, and their
color coding makes it easy to match the right type to your vehicle.
In contrast, “all makes” coolants are formulated for universal use across different vehicles, but this convenience often comes with trade-offs. They may not offer the same level of protection as manufacturer-specific coolants, especially in engines with complex designs or sensitive components.
Also, mixing “all makes” coolant with a manufacturer-specific one can lead to compatibility issues, reducing corrosion protection and potentially damaging your engine. While “all makes” options may seem convenient, sticking with your manufacturer’s recommended coolant ensures better long-term protection and engine performance.
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