There are even differences in the amounts of ethanol in E10 gasolines. If you notice, the label on the pump usually says "this gasoline contains up to 10% ethanol" or something similar. I have a 45 mile commute one way to work. I drive an older high mileage Maxima back and forth to work and fill up at any of a number of different stations along the way, depending on who has the best price. There is one particular Conoco station that I have filled up at a few times. I started noticing that I wasn't going as far before I had to fill up again. I normally get 425 to 450 miles on a tank, depending. With this particular station's Conoco, I get around 385 before I'm on fumes. That is a pretty big difference, enough so to go somewhere else rather than save 5 cents a gallon with them.
Mike in Tennessee
Former 2 time FR owner
2007 Crossroads Cruiser 30QB Fifth Wheel
2008 F-250 Lariat 4x4 6.4 Powerstroke
Firestone Ride-Rites w/cab control