6.4 hemi getting 22 mpg???

I was a little hesitant to buy a 2500 Ram with the 6.4 gasser, especially after reading the low mpg drivers in this forum were getting with theirs. however, I couldn't justify the price of a diesel for the low amount of yearly driving we do.
If the idiot gage in the truck was anywhere near accurate, I was getting 22 at 60 mph hwy on a recent trip through hilly Pa.
I can only guess that the low mileage posted by other drivers was because of higher speeds, a real gas killer.
We will be making a trip from Pa to Tx this coming weekend. This time we will do a comparison on paper to see if it comes anywhere near 22. I will post that Sunday.