You'll get opinions all over the map, on this subject. I run 4.88, with 315/70r17. At 70 mph I run just under 3000. I wouldn't go back, and I'm glad I didn't go 4.56. If I were gearing for 37's, I'd run 5.13.
I ran 3.21s with 35s, re-geared to 4.88 after 2years knowing I was going to 37s. Have the jeep now for 6months on 4.88s and 35s....rpms are a little high for my type of driving and area/landscape. I'll be pleased when those 37s come in next week. If I were to stay at 35s I would have probably went to a 4.56 ratio.
Yeah it's personal preference. The 4.88 on 37" are great to get back to a more stock performance. But who wants "stock"?
If you want better off road performance, go with 5.13.
My wife is the primary driver of our JK. And as such it's more of a daily driver with occasional off road so the 4.88 gears make sense. If I was going to be wheeling it every weekend I'd go with 5.13 gears.
No wrong answers here, just differences in preference.
