Welcome to Ecomodder jrsavoie! You are in the right place to increase your fuel mileage
Do you have some kind of instrumentation? Being able to see real time data will show any imperfections in your driving. I thought I was a conservative driver until I came here and bought a ScanGauge. Talk about a wake up call!
I would shrug off what others say unless they can back it up with data. Don't let them discourage you.
Since you drive mostly highway, aero mods would be the way to go if you were to mod your Jeep.
How is your drive? Can you provide details?
BTW, I absolutely LOVE your vehicle armada that you have!