Well, I am glad to hear that not everyone has the poor gas mileage issue, as well as the hold back feeling, edit: at least I know I am not losing my mind. I know in my first post I said after about 33 mph, the feeling gets lighter, but I am still getting held back at pretty good at higher speeds. Now on to the testing:

Brakes: I drove about 10 miles to my first stop on my way home. I felt several times being held back on a downgrade. When I stopped, I checked all the rotors, and they all felt the same.

DTC codes: dashes than done, no codes

I am really thinking it is a shifting issue. I noticed on the trip home that there were a few times that I was not being held back, I could feel the jeep "let go" when I released the gas. These times seemed like steeper hills. I checked the rpm during these times, and it seemed like I would be at 35 mph and around 1k give or take. During the downgrades that I felt I was really being held back, I was at about 1.5k at 35 mph. Just on my trip home, I couldn't seem to faithfully recreate exactly what was causing the free feeling moments, they were far and few between.

I have an appt. for Friday at the dealership. I will let everyone know what they say. Thank you again to everyone, I always like to have an idea before I go to the dealership. Sometimes they tend to say certain things differently if you are familiar with whats going on.

 

I would just like to post what the dealership found just in case anyone is still watching this thread. They found nothing wrong with my jeep. They said they drove it for 2 miles and did not feel it holding back at all, checked the brakes, and error codes, and found nothing. They did 2 recalls, one of which was flashing a module that dealt with the O2 sensor. the recall said that a faulty O2 sensor may not register as faulty.

Now, when I left the dealership, the vehicle was not holding back at all. it was able to free roll on a downgrade just like I would have expected it to. Everything seemed great. I did notice this morning that holding back feeling starting again, but my gas mileage has definitely improved. I averaged 14.8 city (with HSA on) on the way to work this morning, which is a ton better than the 12.6 I was registering before I took it in.

So, to end this thread, I am assuming that fulfilling the recall and flashing the module must have changed something. Hopefully it doesn't start happening again. Thanks to everyone for their suggestions, I will be turning HSA off as it seemed to help.

 

O2 sensor codes can result in adjusted engine performance. So it is possible that this was your issue... Good luck!

 

I have a 2011 jkr 6sp. I have never seen over 17mpg. I get 12mpg around town, and like 15 on the highway. Jeep has 11k miles on it, and has always been this bad. I thought it would open up a bit, but no. I even tried shifting at very low rpms for 2 weeks, and maybe a half mpg difference. 2.5 tera coil lift with stock rubi tires. How bad Will it be with 35's?