This is the button

 

Ok, I have hit that button before, but all that has happened as far as I could tell was the light flashed a few times. When I looked it up in the manual, it said that only worked in 4 Lo, so I didn't think anything of it. I hit it when I got in my vehicle on my way home, and reset my mpg ave. The vehicle still felt as if it was being held back when I released the gas, but not quite as much.
On to the overdrive: I am not sure at what speed the OD is supposed to kick in, but when I was trying to coast at 35, and I hit OD off, I didn't feel any difference. Perhaps an OD issue is at play.
I would like to point out that even though the hill descent light just flashed like it had before, I did get 14.8 mpg city on my way home. I will have to keep an eye on this over a longer period of time, but perhaps hitting the hill descent helped in some way.

 

I think its your rig. I have an 11 JKU soft top with half doors still stock and I get 16 or so around town and a little over 19 on the hwy. I would def take it to the dealer and have them hook it up to the computer.

 

My '11 Sport Automatic would not coast down hill worth a damn until I turned off Hill Start Assist (HSA). HSA is not supposed to do this, but I'm not alone in getting better downhill coast speed by turning if off. I never noticed lousy fuel mileage because of it however.

The brakes could be dragging for some other reason. Brake calipers can get jammed and cause the brakes to drag. Also, the JK also has computer programs that apply the brakes when it thinks you need help. Next time you think the Jeep is dragging, coast to a stop using minimum brake pedal, get out and see if any of the brake rotors are hot. It they are hot, have the calipers checked out and/or try the dealer to see if ESC and Traction Assist are working overtime.

With SRA tires I could get 22-23 on the hwy anytime. Now that it has MT tires and 2.5" lift it gets 18-20.

 

I just drove my 11 unlimited auto 800 miles today from ny to Kentucky. I got anywhere from 15.4 to 17.1 miles per gallon driving mostly at 74 mph with cruise control on a passenger and the jeep fully loaded front to back with luggage ( I've been on the road for 5 months)
Dave

 

Hmm, HSA is definitely something the 2011 has that the 2008 didn't. I will be turning that off in the morning, and seeing if that improves anything. Thank you again to everyone, I will post back any findings.

 

If it helps for input...I have an '11 JKU with 3.73s. Its an auto. My mileage runs 14 city and even hwy I've never really seen it over 17.

 

I've also never have seen mileage above 17
Dave

 

I've seen 19 before the mtr's/k's haven't seen 15 since...

 

so since breaks, hill descent and HSA have been discussed, and still not getting any better i assume, have you had it in 4WD at all since the problem started. everyonce in a while the driveline will act up. even though the transfer is a manual shift, put it in 4WD the pull forward about 3-4 tire rotations and then put it in 2WD and back up twice the distance, sometimes you can hear the transfer disengage. my old jeep used to do it all the time. had to do it everytime i came off the beach. easy way to check is turn hard left or right and see if either one of the front tires is slipping on the pavement. just trying to help. i too have a 2011 JKU and before i lifted and put 35's on it i would get about 15 city and 20-21 hwy, now i get about 13 city and 17 hwy.