I had 33x10.5s, an ax15 and 4.11s and would get 21 mpg on the highway if I kept it at a reasonable speed. Downshifting to pass/climb a hill was a thing for sure, but that's why we have manual transmissions in the first place, right? As I plan to add more weight, heavier/taller 33s (K02s are way under sized), and hit up more difficult trails, I'm moving to 4.56s but I have yet to test it (Jeep's currently on jack stands).

I also have a stock ax15 Jeep still on 3.07s. With steel wheels and 235/75r15s, I'm downshifting sometimes to 3rd to maintain speed up bigger hills but the 4.0 seems happy at higher rpms, so it's no big deal. 18 mpg mixed is nice. That Jeep is a DD/road trip machine and honestly, the 3.07s are nice sometimes when you just want to devour miles on the highway. No way I'd but anything bigger than these tires on 3.07s though - not unless I had more power than a stock 4.0.

Maybe go with 4.11s and make sure your drivetrain can be reliable at sustained high rpms in anticipation of having to downshift when wanting to pass/climb/etc.

 

I’ll make this a little more confusing than it already is and say 4.56’s and 33s with an AX15 is my personal favorite tire to gear ratio every to be put in a 4.0 powered Jeep . Feels like that’s how it should have been built . I’d rather be too low on gear than too high if intended to use the Jeep over road on a regular basis . If you’ve done much off roading you’ll know how much work it can be with a manual and too high of gears .

 

I'm on 33 12.5s with 307. I excited to swap in 355 axles soon. I dont ever go over about 65, 5th gear is a thing I've never used. Cant lol I pull 4th at about 2500 at 75.

I may regear to 4.56 at some point but no lower.

With 307 it does ok in 4low I rarely use 4hi it doesn't like 4hi I dont drive fast or beat on it.