I thought about that....but that’s awfully low. Had a bunch of Wranglers both 4 and 6s. All had varying levels of trail upgrades, none below 10MPG. Heck my 1999 10” lifted full size 2500 Suburban with a 454 got 12MPG.
I had a V8 Explorer that averaged around 16 mpg - maybe that was the intended number. 60 mpg might’ve been attainable on really long downhill grades.