Water is heavier than gasoline, and water will separate from gasoline (like oil and water). If that small amount of water is sucked into the fuel injectors, it won't burn. That's why you added the de-icer stuff to the non-ethanol gasoline, to mix with the water and burn it without stalling the engine. But I don't think you ever added enough de-icer to bring the total up to 10%.

So, you shouldn't need to add de-icer to your fuel if you're using 10% ethanol.

Alcohols can burn with quite a lot of water in them -- rubbing alcohol is 30% water, and still burns, although not as hot. Ethanol can be added to diesel fuel, and water is required!

I find it amusing how many people describe the horrors of being forced to use gasoline with 10% ethanol, when they spent extra money adding alcohol to gasoline themselves for years! AND paying $20+/gallon for it!

Sue