Ethanol has less carbon per pound versus petroleum because of the oxygen in its molecule. The lower percentage of carbon is why there are fewer BTUs, therefore less energy released when it is burned or used in an engine. That oxygen in its molecule is what contributes to its corrosive properties above and beyond what is caused by its tendency to absorb water. In terms of fuel value: ethanol<gasoline<biodiesel<diesel.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738