If there are multiple complaints, then my suspicion would be somewhere between the refinery and the tank, the blend encountered water.

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If the water is below the pickup tube, then it picks up the phase-separated layer of ethanol, water and gasoline, and the engine will run very poorly, if at all, on that mixture.

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When any volume of this blend comes in contact with one-half of 1 percent (of its own volume) of water, a condition called 'phase separation' occurs. For 10,000 gallons (of blend), that's 50 gallons of water.

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