I've been averaging about 17-18mpg in town and on the highway. I have 4.10s, 35s, 6spd and a tuner. I drive pretty conservative, and am happy with the power output running the 91 superchips tune.

 

I have no issues with anyone being a skeptic. I am still running my 3.73s as what I saw on this forum overstated what my results would be with 35s, and I've since convinced myself to go 37s before doing a gear swap.

I live in a very flat part of the country, and I need to drive 2 hours to see more than a 150' elevation change. I also out of the gate installed headers with a heat barrier coating, the CAI and exhaust. With the Flashpaq, I ran both 91 and 93 in the summer, with an 87 octane test on a long trip to see the differences, I opted for the 93. When the weather started getting cooler, I backed off to 87 simply because of the longer time to get to operating temperatures and longer times in open loop. I also run a 180 degree thermostat in the summer, and a 195 in the winter.

Lastly, my JK doesn't weigh all that much. To date I don't have bumpers, armor or a winch. I also don't have the back seat in so I'm sure it's not weighing in at much over 4,000lbs.

 

I have the 35's and I regeared to 5:13 whcih brought me back to little better than factory. My mileage is still crap. The bigger the tires the more gas you are going to burn. Sure you can tune and due all the mods you want related to that, but in the end it's not a Ferrari or a BMW. It's a jeep with a 3.8 liter sewing machine engine. Enjoy the Crawl and the View. Life is too short to worry about superfelous "STUFF"

 

dumb question, BUUUUUUUT........ are you able to just re-gear the rear or is everyone re-gearing both the front AND rear?? I have to ask b/c I haven't read anyone mentioning doing both and I know how much $$ I had tied up in gears, etc when I had them changed in my mustang; so I could only imagine what the price would be to do both a front and rear change. I figure that you have to change BOTH b/c it would make sense that both front and back would need to be the same ratio to run 4x4 correctly, but not positive on it. Never had to change gears in a 4x4 before.

 

You are correct...For a 4WD JK, you need both front & rear axle to match, so there wont be any conflict from the mismatched gearing...

 

With my 6th speed wit 4.88's and 35's I get BETTER gas mileage than when I had 3.21's because the motor doesn't have to work as hard, you can actually USE all 6 gears!

 

when you say better what are you talkin i get 15 in town stock 3.21s and 22 on highway but the in town is where i do all me drivin. ill be on 35s in spring and leanin toward 4.10s or even 4.88s