i just bought some sea foam ill let you guys know how it works!!
and btw i have CEL on and its throwing about 6 codes

 

17mpg with 3.5 suspension lift , not so beefy tires lol

 

87 Renix 4.0, AX15, NP231, 3" Lift, 235/75/15 gets around 18mpg pretty regular.
Wifes Jeep....
95 4.0HO, AW4, NP231, Bone stock, 235/75/15 averaged 18mpg when we use to drive it.
80 Ford Bronco 7.5L C6 Auto, 3.50 gears, 4x4, Detroit Locker in rear, 31x10.50x15 Holley 650 carb, Weiand Stealth Intake, Headers, and IF I drive it under 55mph and gently roll the throttle I can get 12 out of it.

I would suggest you try driving your jeep in direct, not overdrive, and you will see your MPG come up. You just lugging the little engine to much and its taking more fuel to keep it moving.

 

15 was in city lol i dident mean highway and i have a broke Exhaust on it.

 

I get about 250 miles per tank. My odometer is off by 2/10ths of a mile.

I took it to Oklahoma this weekend. It was comical to say the least. Pulling a small 10 foot trailer with two motorcycles, lawnmower and two bicycles I used 5/8 of a tank driving 200 miles with the wind at my back. Averages out to 16.6 MPG. On the way home with an empty trailer driving into a stiff 30-40 mph wind I barely made into my town. Had to stop on the outskirts to put some gas in just to make it home. Which about 4 miles from the gas station.

Went back Saturday. Drove down with no trailer. Used 3/8 a tank of gas with the wind at my back and only my little brother and lab in the jeep. Drove about 200 miles and average Mpg was 25 for the trip down with just the jeep. On the way back had my Dad, Mom, lil bro, dog and bags of stuff we had for their move. Used 5/8 a tank with little to no wind. That equals 16.6 MPG. Pretty big difference with the weight and no wind at my back. Did have some cross winds for about have the trip driving back.

That's with a 3" lift 31's and stock gears. (3.55)