[IronJack]

It didn’t happen. Ethanol doesn’t “crystallize.”

This reporter is an idiot. But the “blame ethanol” crowd will eat it up.

[PSYCHO-FREEP]

Partly true, but the Ethanol reacts with pewter and aluminum parts that create Aluminum oxide crystals. It is the result of massive nonferrous corrosion.

[yefragetuwrabrumuy]

Ethanol is hygroscopic, meaning that it will attract water from the air, which is absorbed into the gas. The water bonds to the ethanol, becoming heavier than gas and the mixture sinks, lowering the octane level and causing performance problems. This is called Phase Separation. Cold temperatures will accelerate this separation.

Water with only 1% ethanol will freeze just a little below 0 °C, whereas water with 95% ethanol will freeze pretty close to -114 °C.

The zinger is that ethanol has a long time to absorb water from the air, which is usually high humidity around a marine gas pump at the dock. Their large tank, with a lot of ethanol, eventually gets a lot of water and ethanol mix at the bottom of it, as it is partially emptied, then refilled, then partially emptied again.

Add to that just ordinary water splashed into the gas at some point.

So if you fill up your engine when the gas pump tank is low, you might get a lot more water than you think. And in cold weather, bingo, ice crystals.