so they use less Toluene and other aromatics that are highly corrosive. The oil companies realized the public was figuring out the problems were their blends and not the ethanol. Reducing the aromatics has made it more expensive to get higher octane ethanol free gas. Ethanol is a much cheaper way to get octane. That's why they embrace E-10 & E-15. It has the octane without the corrosion issues. It even takes care of the water in gasoline issue as long as it's not too much water for the amount of ethanol.