I can say that with a 270 mile trip, you should easily make that on one tank. I've taken the drive from here to Vegas which is right around the 300 mile mark and arrived close to empty, but not entirely (low fuel w/15 miles battery left due to MM). I will admit, I was a bit disappointed in that figure, but my car also has about 73K gas miles and no history or engine maintenance other than regular oil changes. I recently replaced the plugs in it and although they looked practically new, I feel better. I will be doing that drive again this weekend and am looking forward to the comparison. I think the original 350 mile estimate didn't take into account sustained 70-75 mph drives which do have a noticeable affect on mileage.