Here are the details.
2009 JKU 3.8L with 3.73
P255/65R17
Daily driver and weekend toy.
Area altitude is 620' ASL and flat as a pancake.

I drive about 35 miles each way for work a couple times a week (55mph 2 lane). I got this JKU with the intentions of building a family toy. I had my heart set on 35's but now I am having major second guesses on this. I am running 2.5" spacer lift and 1.5" wheel spacers. My plan was to suffer through the sucky performance until I can regear...probably 10months at least. Now thinking about getting 10mpg isn't too appealing anymore. I am thinking now going with a 33 or even a 265 series to keep the performance as near stock as I can.
Then, when I have the money for the regear I can go to 35's or maybe even 37's
I am really torn as I need to be able to drive this thing every day, but now I am worried that the jeep won't look "angry" enough with the smaller tires.

How bad will the 35's kill mpg at 55mph?
How crappy will the performance be? I was going to flashpaq it, but that is a third of a regear cost. Ugh!

Thoughts???

 

Manual or auto?

It won't be that bad either way. You won't get 10mpg either, you'll lose a few but that's a given...

Lots of guys running 35's and 373 as a daily drivers.

The only thing you will regret is not getting at least 35's

 

I have 2011' with auto, 3.73's, 35's, and procal, computer say getting 15 mpg.

 

Oh, and I drive with O.D. off 90% of the time. I drive 23 miles each way to work, never get over 55mph.

 

I have an 11' JKU auto w/ 3.73, 35's, aftermarket bumper, winch and a leveling kit. I also have a Flashpaq and I'm getting 15-16 mpg driving 20 miles each way to work.(Getting above 55 mph) I would definietley go with 35's. The mpg difference is not that big of a deal as long as you get at least a flashcal to reset your tire size.

 

I was in your same situation. 11, jk, auto, 3.73 gears, and 35s. I drove like that for a little over a year. My mpg was average of 13.7 over that time period. I used a phone app to track and yes it is corrected with a pro cal. The jeep computer is off on mine by about 2 mpg so I prefer to look at actual calculations instead of what the jeep says you are getting. I found that I got the best gas milage above 75 mph with od on due to the engine rpms. Other options are to turn off od like others have stated.

I recently switched to 5.13s about 1 month ago and I am seeing almost a 2 mpg increase in fuel.

Bottom line, I say go with 35s if that is what you want. The difference in fuel between that and 33s will not be significant.