I usually try to buy Shell gas as well, I seem to get the best results with it. Also, you should get better mileage if you find a station that doesnt mix ethanol. It's getting harder and harder though to find stations that don't have the "Mixed with up to 10% ethanol" Ethanol has less energy than gasoline and thus decreses your power for a given amount of fuel so you burn more fuel to make up the power. I don't know how much of a difference it makes overall. If you consider that it has 10% less kick and that most internal combustion engines are only about 20% efficent at best: .2*.1 = .02 or 2% power loss.......... whether or not that's the case, who knows. I've heard of people getting noticably better mileage running non-ethanol blended gas, my Durango on the other hand doesn't seem to have a care in the world as long as it's gas, i still average just plain sh!tty with it.........