Dex cool vs Zerex GL05

Davidtj

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So I know in the early days Gm had issues with dexcool and got a bad name. Found this on another form thought might pass it on
The other day I noticed some sediment buildup in the bottom of my overflow reservoir. So today I took it out and cleaned it. I had some leftover Zerex G-05 HOAT antifreeze, which up thru 2012 was the Chrysler specified antifreeze. I wondered if the sediment came from the factory HOAT so I placed a call to Valvoline and spoke to one of their antifreeze techs, named Ronnie. Here's what I learned. 1) Valvoline makes the HOAT for Chrysler. Zerex gets a yellow dye while the Mopar version gets a pinkish dye. Chrysler buys the stuff in bulk. Automakers have been known to throw stuff in the mix to help prolong the life of rubber hoses or lubricate the water pump. This is a common cause of sediment drop out in overflow tanks.2) The Mopar OAT for 2013 and newer (which is expensive as hell from the dealer) is the same as the latest Dexcool. I debated this point with Ronnie because I had read a SAE article where Chrysler stated their new OAT doesn't have the additive 2-EHA which has been known to soften plastic gaskets and was the cause of so many cooling system and intake manifold gasket issues for GM. This is why Ford and others shied away from Dexcool when it first appeared back in the early '90s. Ronnie went on to say Valvoline makes the GM Dexcool and around 2006, GM stopped using the 2-EHA. Around 2011, the ingredients in Dexcool were revised again. So I asked why is Chrysler stating the only OAT antifreeze to use in the 2013 is theirs and he said money/marketing. Another company currently makes the new Mopar OAT. While Chrysler didn't publicly announce the chemical composition, Valvoline got their hands on this OAT and ran some tests. Come to find out it's formulation is the same as the latest Dexcool. Same stuff, just different color.Ronnie finished by saying Valvoline has been getting a ton of phone calls asking what Zerex coolant can be safely used in the 2013 lineup of Chrysler vehicles requiring OAT. The advice from Valvoline is buy the dealer version if it makes you feel better or buy the Zerex Dexcool for about half the price and get the same antifreeze except for the color.
 
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The other day I noticed some sediment buildup in the bottom of my overflow reservoir.
Today, this should be non existant. I'd blame some local product... like water during spring runoff.... I remember in Alberta, there was a market for darker beer during spring runoff.... stronger too

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