You can read online some of the White Papers issued by Kenworth or Cummins regarding fuel economy. Below 50 mph it is the rolling resistance (tire size & type; then drivetrain), above 50 mph it is wind resistance.
Narrow ribbed tires (have a look at the "steer tires" on a big truck; or those for city delivery), with a reasonable inflation pressure (too high a pressure is a safety problem) is a big part of the answer. Stock tires at no than 70-series is a good idea in "highway, all season" type.
Synthetic gear lubes is a second. Same with engine oil. Jeep engines do fine on 10W-30, use a quality filter as well. Minimize idle time, avoid drive-thru and plan driving route to maximize steady-state speed (speed limit is something to never achieve around town).
On the road the penalty for running 70 mph (time saved) is not offset by fuel economy penalty (acceleration penalty) for trips under 300 miles. Running 65-66 works better for not having to slow down or pass "slow traffic", etc.
Progressive shifting is not quite applicable to Jeeps, but a steady, long acceleration from stopped back to cruise speed is great. I do it regularly with the overhead readout. Get a vacuum gauge to learn how to accelerate reasonably.
Nice photo of good looking air dam above, thanks for posting that.
i only run my tires at 36psi. the flexalite fan should be in today soo well see how much that helps.
