I know, my wife gets pissed when I talk about seeminly simple stuff in overly complex ways. I don't do this all the time, but when i'm trying to get a real accurate measurement of my mpg's over the course of several tanks, I will do this for a few tanks.

 

i wish i got 18.54 mpg....[:@]

i get the 301+ miles, but its more like 20+ gal to fill the son of a bitch up.

 

ScanGauge ll it will give you every possible reading on your truck! including exact MPG and instantanious mpg trip mpg ect...

here's the link.. check it out!! NOW! http://pureenergysystems.com/store/ScanGauge/index.html

 

i filled up a couple of days ago and put 30 bucks (while it was already in empty) at $3.95, and i went 93 miles before i had to fill again, i divided 30 (bucks) /$3.95 (dollars)=7.59 (gallons)-93 (miles)/7.59 (gallons)=12.25 (mpg)