I got a 2012 jku rubicon 6 spd I'm going to run 35s what gearing should I go with. I know I could run the 4.10s but I don't want to lose my craw ratio. I would like the gearing on road with 4.10s and 35s but I think it will be alittle fast going over rocks.

 

Nobody want to talk about gears :((

 

I'm not that experienced with gears, but from what I've noted on here most people with rubi's, that come with 4.10's factory, I think they're content with the 4.10's. But do more research and look up a gear chart.

 

Gear chart shows 4.56 will return it to slightly lower gearing than stock ratio with 35s. I'm waiting for some one to chime in that has the same situation I do not want to lose my crawl ratio but I don't want to much more either.

 

I have the same set up you are talking about. I wish I had years of experience I could impart on you but dont. Frankly, I still find myself asking why Jeep didnt put a V8 in the damn thing. If someone knows the answer to this please let me know because im really having a tough time with this one.

THat being said I have a 2012 Rubicon in 6 speed sitting on 35's. The truck is slow. PERIOD. Then again Im coming out of an infinity G37 coupe which does 0-60 in the high 4s to low 5s.

ON the highway 6th gear is great if you know you will be at 70 for awhile and on a flat surface. If you hit a hill you will not sustain 70 in 6th. You will need to downshift to 5th. Still its not fast and to sustain 70 or spead up you need to at least quarter throttle it.

3rd gear at around 2700 RPMs is the most powerfull spot in the powerband from what I am seeing.

The charts say the 3.6 on 35s should have a minimum 4:10 and a max 4:56. I am considering 4:56 but need to know more about what Im getting into before I make the swap.

1) I want to know what it will do to my mpg's since this is my daily driver
2) I want to know what 4:56's will do to my 1st gear. Right now im getting about 15 mph out of it. PS - You can start from a dead stop in 2nd gear without stalling.

I hear that 4:56's are hard to find but I would imagine this will change in the future as 4:56 is an odd setup for the older jeeps. The pentastar will change that I beleive.

Next up from 4:56 is 4:88. I have no interest in the 4:88's as it seems to be the most popular gear for the 07-11 JK's.

 

I'm running 35's on my 2012 3.6L with stock 3.73 gears. No problems at all. In fact I can run in the 90's if I want to, but don't very often. Consistently run 70-80 like it's nothing. All I have extra is a DynoMax catback exhaust. No plans on re-gearing for me unless I bump up to 37's.

 

I don't think you would do well were I take my jeep with that craw ratio. But I would like that for on road driving.

 

Im sure I can hit 90 if I get everything out of my gears before I hit 6th. Maybe I just need to get used to the Jeep in light of the fact that im coming out of a sports car. Also I need to point out that I have not recalibrated my computer for the tires size so im going faster than the speedo is telling me.

If you have an auto trans 3:73s are considered minimal. 4:10's and 4:56's are considered optimal for highway driving. Im surprised you are not complaining.

 

I have a 2012 6sp. I went with 4.56's and 35's. Perfect combo......

 

Don't have a 2012, but on my 2010 auto i run 35's with 4.88's the improvement over the 4.10's is so much better and i can still run on the freeway and offroad same as when stock. I chose 4.88 because i plan to move to 37's at some point and that combonation will put me back to stock ratios.
The extra power of the 2012 will make a big difference and I don't have all the gear ratios for the new auto but 4.88's but if i recall correctly, it 4.88's should keep you in the powerband for higher speeds and still gove you nice crawl ratio.
I recommend to really understand your overall driving habit and get the gear setup to fit your style - if you are happy with stock, get as close to stock as you can - my recommended ratio was also 4.56 but i'm glad i went with 4.88 and now i get good performance, good gas milage and am ready to move to 37's without having to do another gear change