Adam, your correct........BUT if your car sets for any period of time ethanol will seperate from the real gas in your tank. Most of the refineries want to sell the ethanol blend because they can use a cheaper, lower octane gas. Then add ethanol to increase the octane. What that means is if it sets for a period of time and seperates (and it will) you will be burning a lower octane rated gasoline or either the pure ethanol, depending on how much is in your tank. And like most people that let their cars set over the winter they fill up. This means in the spring when you fire that baby up you will be pulling up the lower half of your tank which would be nothing but pure ehtanol or water if there is any in the gas. Either way you will NOT be running on 91 octane (or whatever you put it, I only use 93 pure gas) Ethanol is NOT good for your car, lawn mowers or anything else for that matter. Just run pure gas and be safe. It is very easy to check for ethanol, just add about one inch of water to a 20oz coke bottle and fill the rest with the gas from the pump you want to check, shake it up well back and forth so the water goes from the top and bottem, then let it set for a couple 2 or 3 minutes. Any increase of water line will be the amount of ethanol you have in that gas. I checked 5 local gas stations around my area and only found one that has real gas. You can also go on line and lookup who has pure gas without ethanol in your area and you may find some listed.