If you are concerned about your MPG you are posting in the wrong place. Fill your tank, drive, fill your tank and do the math. Do this a couple of more times and you will get a pretty good idea of your MPG after about 1000 miles of driving. The difference between getting 8 or 10 MPG will turn out to have cost you less than $100 over that 1000 mile trek. That being the case, how important is your MPG?