Why are the milage ratings so much lower on flex fuel vehicles than ones with the same engine that run on gasoline only /

As I ask the question I realise that part of the problem is that a gallon of ethonol contains less energy than a gallon of gas so does that mean when running on gasoline the milage would be the same?

You are correct ethanol has less energy per gallon than gasoline. It also has a shelf life because of it's attraction for water from anywhere it comes in contact with it even from the air. Here are some interesting facts that I dug up about ethanol. It takes 1.5 gallons of ethanol (E-85) to drive as many miles as one gallon of gasoline. Ethanol increases the vapor pressure of gasoline by 1 psi. resulting in higher evaporative emissions of Volatile Organic Compounds, while tailpipe emissions of Acetaldehyde increase 150%. Ethanol permeates the hoses and lines of automobile fuel systems resulting in a 50% increase in VOC emissions for pre 1995 cars. Ethanol dissolves oxide scale from the walls of pipes and tanks, subjecting the systems to internal corrosion, which leads to leaks. Every gallon of ethanol sold removes 53 cents from highway funding. It takes 1.4 gallons of gasoline to produce 1 gallon of ethanol..........

aztec said it best. Ethanol is not the way to go, and I can dig up further studies showing the cost to the environment in terms of erosion and not rotating crops by planting corn year after year on the same land is bad for the soil, raises prices for food (almost everything has corn in it, whose price has skyrocketed do to a big proportion of the corn crop going to fuel and not food. It's lose lose. Mike www.fromcartofinish.com