i get 18.5-19.5 mpg with about half highway half city driving. this has been this way since i bought it 3 month ago. 98 4.0 5spd. always shift under 2.5K. i agree w/ the speed, keep it under 75 and shift like a grandma and you will see an increase in mpg.
98' TJ sahara-white w/spice hard top-5 spd-I6-all stock
70' CJ5 "Dauntless V-6"-3 spd-twin stick pto ramsey 8000lb winch-green body/black bikini/aluminum hard top-2" lift-mudders