I just got mine a few days ago as well, make sure you calibrate it! When I had mine it said I was getting about 26MPG on a tank and only used 13.1 gallons, but I actually only got 20MPG and used 15.1 gallons.
Hopefully after calibrating it that time it will be more accurate.
Mine is on the way as soon as the group purchase on cleanmpg.com wraps up.... what's up with calibrating it? Is there instructions in the box for how to?