One con of ethanol that no one seems to know

The vapor phase above the liquid ethanol is such that the vapor in a closed container is explosive.

Now, you are probably thinking..."gas vapor is explosive too!" WRONG. Gasoline is not explosive until you have the proper air:gasoline vapor mixture. Hence the compression stage in the pistons. At normal temperature and pressure, this explosive mixture does not occur.

Ethanol has the proper volitility to create an explosive vapor phase at ambient conditions.

So what does this mean? Well, introduce a spark to a gas tank and it shouldn't explode(it may if it mixes just right). Introduce a spark to a tank of ethanol and you can kiss your ass goodbye.