Mpg to date, 21 fillups.

Miles Per Gallon
29.5
32.7
30.5
31.1
26.7
32.5
32.9
33.1
31.7
29.8
30.8
31.3
29.9
29.8
31.7
26.7
30.2
31.1
31.7
29.4
33.1
32.31

My current mpg based off of 21 recorded tanks.  My dash mpg displays 32.4, so it's doing a really spot on job of calculating.  I'm using the app MPG for Free to record and calculate my mileage.  It also outputs the data as a .csv file which you can email right from your phone.  A great app.