..At least I think you did. Oxidation is a property of water when in contact with metal, distilled or not. Water is highly corrosive whether distilled (which can leech minerals to acquire balance), or tap (which has too many minerals, albeit dependant upon the actual hardness of your water). Corrosion comes in two forms, scale build-up and or rust, a disolving of mineral salts, and oxidation.

But Ethelyne Glycol is also a highly corrosive substance (especially when heated), so you add the two together to get the cooling properties of water, and the antifreeze qualities of EG, but you also get serious corrosion, so you add silicates, and an anti-corrosive agent like amines, nitrates, or (currently in the green stuff), phosphates. But the Europeans found that due to the extreme hardness of their water, that the phosphate corrosion inhibitors cause these minerals to "drop-out" of solution, and form either a mineral slurry, or "stalagtites" that break loose and clog restricted passagesways when combined with other similar mineral formations at the same location. Or both. Then you add to that the electrolysis caused by multiple-metal engine components (aluminum, brass, copper, iron, etc.) with this slurry flowing through it, creating a negative electrical field, adding to that, the erosion caused by the abrasive liquid "sand-blasting" the cooling system and it's ancillary components, you have the recipe for premature cooling system component failure.

All of this also causes cavitation, erosion, and clogging that results in hot-spots, that in turn results in uneven cooling, and overheating of critical engine components. But I haven't even mentioned what happens when the "coolant" comes in contact with the extra-hot surfaces of the cylinder head. When his happens, the water in the "coolant" turns to steam, and is repelled from the heated surface, to only come in contact with cooler liquid, that causes the steam vapor bubble to explode, sending a shock-wave from the detonation back to the head, where it removes all protective coatings that are there and can actually result in a deterioration of the metallic surface itself.

Mercedes-Benz Antifreeze, Anticorrosion Agent addresses the phosphate issue by replacing it with a specially formulated compound produced by BASF, called "G-05", or Glysantin. This eliminates the minerals from "dropping out" of solution, But it does not adequately address the detonation issue like Evans NPG+ does by replacing the troublesome water component entirely.

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Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."