Apparently you had American Green with the OAT benzoate, and then G-05 and Japanese formula with benzoate. Only G-O5 of the 3 is considered an HOAT and the other 2 are considered IATs but that may be a misnomer. Anyway, all 3 may have contained benzoate but none of the three are known to be gasket eaters or to slugde due to air.
Then along comes Dexcool and 2EHA. It's believed to be a plasticizer and Ford, Honda and others swear it off. Ford stuck with the Green and didn't appear to ever want to get on the OAT bandwagon until finally settling on G-05. Japanese come out with an extended life coolant with a carboxylate inhibitor sebacate. Which is also a plasticizer. And Peak Global contains benzoate but also some other unknown inhibitor that might be sebacate.
What does that really leave that's not a carboxylate acid with plasticizer ability but American Green and G-05?
I'm sure you can use Japanese POAT coolant in a FF Japanese car without any gasket deteriotion. And I think you can use Dexcool in a late model '05+ GM vehicle without problems. It's the earlier models and the back-specing that might be the problem.
It's too bad for OATs and HOATs though. Dexcool does have a very long life and protects both aluminum and iron well. It doesn't have silicates that have a short life and may abrade the waterpump seal, no phospate to react with hard water, and no borates that could corrode aluminum if the other inhibitors are depleted. But none of that is as important as protecting your engine gaskets or not sludging up.
Then along comes Dexcool and 2EHA. It's believed to be a plasticizer and Ford, Honda and others swear it off. Ford stuck with the Green and didn't appear to ever want to get on the OAT bandwagon until finally settling on G-05. Japanese come out with an extended life coolant with a carboxylate inhibitor sebacate. Which is also a plasticizer. And Peak Global contains benzoate but also some other unknown inhibitor that might be sebacate.
What does that really leave that's not a carboxylate acid with plasticizer ability but American Green and G-05?
I'm sure you can use Japanese POAT coolant in a FF Japanese car without any gasket deteriotion. And I think you can use Dexcool in a late model '05+ GM vehicle without problems. It's the earlier models and the back-specing that might be the problem.
It's too bad for OATs and HOATs though. Dexcool does have a very long life and protects both aluminum and iron well. It doesn't have silicates that have a short life and may abrade the waterpump seal, no phospate to react with hard water, and no borates that could corrode aluminum if the other inhibitors are depleted. But none of that is as important as protecting your engine gaskets or not sludging up.