My last trip on the highway (DEN to ABQ) netted 20.2 (hand calc) on the way down and 18.2 on the way back. Going down I drove nice and easy (about 70mph) and took the scenic route...US HWY 285. Coming back I took I-25 and ran between 82-86mph. I run power service at each fill up and have my BDDL set on the performance setting. Having said all that I don't think that 22mpg is out of the question. He may just have that one particular engine that runs really well and gets exceptional mileage.

 

I Run Howes in everytank and that seems to help i've ran it w/ out and didn't get as good as milage but with Howes its bumps it up a little bit.

 

34k 55 to 60, cruse on, drove 208miles,
some city miles. stopped for lunch.
overhead said 26.9, hancaled 26.1

gregg