I have a 07 Jk 2 door X edition on 35's, a 4 inch skyjacker lift,with 3:21 gears. What would be the best gear ratio to get back my fuel economy as it is an 80 percent daily driver, but still have the power to do some mild trail/rock crawling every now and then? Thanks

 

Auto. 5:13 or if you ever think your gonna go 37's 5:38.
6 speed. 4:88's
I run 5:38's with. 37's and still don't feel its enough out here in the mountains.

 

Thanks I will start looking into them.

 

5.13 with that d30 is my opinion.

 

As far as I know, nobody makes 5:38s for a Dana 30 and if they did the pinion gear would be tiny.

 

For an auto, the 5:13's are best for performance but I stayed with a 4:88 because of my concern about pinion gear size: It's relatively flat where I live and rarely tow anything.

 

Richmond gear used to make them. I ran them for over a year with 37 mud grapplers , unlocked.
Held up fine, I was just careful.
And yes it was tiny, you could see the bearing behind it.

 

If you didn't re-program for the bigger tires, your mpg will look worse than it really is.

In '07, the gear choices from the factory were 3.21 and 4.10. Since you haven't mentioned the lack of power now, is it possible you have 4.10s in it now?

 

In my 07 I went with 5.13's and I thought they were too much.

I recommend the 4.88's as a DD and trails.

Makes the RPM in the correct range for everything.

 

I'm gettin' ready to do new tires and wheels next month and have been scouring the forums for input. I'm in an 09 6sp with 3:73's and have been tossing up 33's vs 35's .. Obviously, 35's is the choice that i WANT, but I also don't want to destroy my rig or the fun of driving it. I'd be tuning it up with a programmer immediately as i've seen where that helps some. Any of you guys running that set up?

I've seen it go both ways... Some people say it's horrendous, some say it's just fine.. Re-gearing at some point is almost always recommended from both points of view, of course... and i'd do that some day when money allows.. Just wanna make sure i'd be "ok" until then!!