Well I have roughly 17,000 miles on her now I got 16.0 twice (I do check every tank manually) but usually average low 15's empty driving mostly a 80% Hwy commute. Traded my brother one week (10 days actually) and got 17.2 doing the same routine in a 2001 AWD Denali

Truck runs ok but not nearly as strong as by Brother-in-laws 05 CCSB Ford 6.0

Had the truck in twice and they say everyting is ok in the motor department. The only thing they cannot seem to fix is the Drivers seat will not keep it's memory and a whistle on the passenger side door. Would that qualify for a lemon?