One draw back compared to gas is you can't let the fuel sit too long in an unsealed container (like your gas tank) because the ethanol absorbs water quickly....so if you only drive your car like once a month, you should find a way to seal up your fuel cell. "They" say that you should not let the car sit for more than 3 weeks at a time with e85.....so, I guess that means I have to drive my car a few times a month.....darn.....:D.