How can antifreeze manufacturers claim their product is all makes, all models or universal? They really can’t. Generally, all makes all models universal antifreeze is 96% ethylene glycol and just 2 to 5% inhibitors.

The truth is, color is not a reliable predictor for what type of coolant you have. For example, OAT coolants are usually orange, yellow, red or purple. HOAT coolants are orange and yellow for the most part. Then the older IAT coolant is green.

Mixing universal with Dexcool antifreeze will almost guarantee the mixture will gel and sludge in your cooling system. The green and orange coolants do not mix. When mixed together they form a gel-like substance that stops coolant flow and consequently the engine overheats.

Do not mix Dex-Cool with regular anti-freeze! Dex-Cool is a specially formulated GM coolant which will not mix with traditional coolants, and was used in various GM applications up through the 2004 model year. Likewise, what happens if you use the wrong color antifreeze? The green and orange coolants do not mix.

Regular antifreeze is composed of water mixed with methanol and ethylene glycol. DEX-COOL, as well as other organic acid antifreezes, are not glycol based. Instead, DEX-COOL is created out of a combination of different phosphates and silicates as well as the organic acid technology itself.

Back in 1995, GM began to use “Dex-Cool” coolant in its vehicles; in fact, you may very well be driving a vehicle that uses Dex-Cool. In total, GM received 68,114 claims, most of which were paid until GM declared bankruptcy in 2009. Now, some closure is coming to the remaining owners who have filed a claim.

AutoZone Antifreeze/Coolant Universal CONCENTRATE Dex-Cool Compatible *5 Year/150K Mile Protection* 1 Gallon.

Dex-Cool uses a combination of organic acids as its corrosion inhibitors (OAT – Organic Acid Technology). GM believes that it provides better corrosion protection than regular green coolant for cooling system composed of different metals (primarily iron, aluminum, and brass), and provides a longer 5-year service life.

On GM’s own consumer site, the debate regarding its Dexcool antifreeze continues. And in mixing any antifreeze with water for a 50/50 mix, the use of distilled water is highly recommended.

distilled water