last year when pulling my 5th wheel and driving my 06 dmax crew cab dually, it was just me and my 2 kids, our luggage and the trailer was empty (no food, water, toys ect....). I had 90 gallons of fuel in the aux tank and the main tank was empty. We rolled accross the scales and weighed in @ 23985 lbs. Got 11.7 mpg overall on the 2200 mile trip. I thought that was pretty good for what we weighed in at.

 

mine is up 1.25mpg-but i just put on dyna-trac free spinning hubs two weeks ago!