I get around 270miles to a full tank. When I go to the fillup on E (directly, I only put in about 9.4 gallons in) wherein the actual fillup is 13. I have 261 currently on my tripometer and it is directly on the E as well. I remember looking at the tripometer when it was on half tank and it read about 124 also. I'm not sure if I'm having the same type of "problem" or situation as you are but I am experiencing the same thing.