I drove 60 highway miles this morning. After resetting the Lie-O-Meter, the overhead read 22mpg for most of the drive and never fell below 21mpg (at 70mph). I have never seen that before. Normally it would settle between 18-19. My buddy saw similar results on his 2003 5.9 after a fuel filter change. Now it's wait and see if this also fixed the intermittent bog between idle and half throttle. If that was indeed the original filter it was way overdue at 81,000 miles.