Thanks for all the help guys

 

From what I have read be careful with 15 inch wheels I have read mixed reviews on if they will clear the brakes. I have not re-geared but I would go 5.13 with auto and 4.88 with standard.

 

I am very pleased with my 5:13s.

 

I agree. I had 5.13's installed because I don't have a rubi. It runs good in town but still tends to shift a bunch on the highway. But it really depends on where you live, around here is a lot of hills. I wish I could have installed 5.38's, don't get me wrong I'm satisfied with the 5.13's, just not overjoyed about them. Live and learn.

 

I've got about 4000 miles on my 5.13s with 35" Goodyear MT/Rs now, and it made driving the Jeep much more enjoyable. No it's not a hot rod by any stretch of the imagination, but it can get out of it's own way now and easily merge onto the interstate. Another big plus is that it doesn't constantly down shift on any slight incline. Oh ya She also has an auto tranny, Superchips programer and MBRP cat back.

 

5.13s or 5.38s are the way to go. A whopping difference of less than 5% between them. That's about 125 rpm difference at cruise speeds and there isn't much of anyone who wants less gear off road.

The big difference and the killer of performance and efficiency in the automatic is kick downs and unlocking the converter. With 5.38s that's going to happen less and otherwise with a nominal gain in rpm their isn't going to be a perceivable difference in economy.

So I would jump on the 5.38s and be done with it. Keeps the door open wider for 37s and will push your JK around just fine if you should add some additional weight.