Been my experience most guys pad their real MPG 3-5 mpg to justify the expense of owning a miniture big rig.
While I would tend to agree, the 10mpg he's reporting is bad. However like suggested, we need to know your mpg after a relatively long highway run. Fill-to-fill calculated by hand, not using the overhead console for mpg and report know your speed.
FWIW, while at a 55-60mph cruise, my 99 24v long box 4x4 quad cab got 18 according to the overhead console, which I never verified by hand in the time I owned the truck. My buddy has an 04 24v crew cab 4x4 and his would show the same mpg at the same speed as mine. I know in winter, the overhead console would struggle to hit double digit mpg during town driving. I don't put a lot of stock in those reported numbers but it is something to watch for consistency if anything.
