Is ethanol gasoline good for the environment or causing you to fill up more often?

Ethanol is consider a biofuel alternative to gasoline.  It is produced from the fermentation of sugar from foods such as corn, sugar cane, etc. and it also can be produced by the hydration of ethylene from petroleum production too.  Many gas stations advertise ethanol additives in their gasolines and that by purchasing their ethanol gasolines you are helping reduce pollution in the environment, that your car will run better, etc.  Is this true and what are the things you may want to know…

Not all vehicles do well with ethanol based fuel.  Your gas mileage could be reduced and unknowingly you could be filling up more often. People who have reported reduced gas mileage with ethanol based gasoline are some hybrid owners and people with older cars. 

Of course for you to know whether ethanol based gasoline is affecting your gas mileage or not, you will have to test your own vehicle for results.