I have a 2012 4 door rubicon auto im running 37s now on the 4:10s.
So my question how are the 5:13s with the new drivetrain? If am in the process of buying a pop-up camper and i tow a boat. I drive from florida to ny once a year. My 37s have about 1 year then im going 40s unless a smoking deal comes along on 40s might be sooner.

Anyone with a 2012 auto please comment on your gears 4:56 , 4:88 , 5:13 and tire size.

 

I own a 2012 Rubicon Unlimited automatic and just installed 4.56 gears and running 35" tires, I personally think that is the best set up for 35" tires. I am running 2700 rpm at 70mph and getting 16.8mpg. There is a chart on this forum that jpop did for the 2012, if remember correctly for an auto 4.88 for 37's and 5.13's for 40, but I would find the chart to make sure.

 

Newbie question alert. Got Nitto Trail Grapplers in 285/70/r17. THe gear chart in the FAQ shows I need to re-gear, possibly to 4.56. What is the cost of the labor for this, and do you need to go to 4wd specialist or can you just go into a good shop and have this done?

 

Here's a link to the chart in the FAQ. Just scroll down a bit for the Pentastar chart.

https://www.jk-forum.com/forums/showthread.php?18617-MODIFIED-TECH-FAQ-Answers-to-the-Questions-Every-Newbie-Has=&p=211276#post211276

With your situation and agenda 5.13s are probably the best path. More than enough gear for the rigors of 37s and towing while keeping you at a good range for when you upsize your tires to 40s.

Also, here's the chart.

 

Thanks for the info and chart jpop.

 

Thanks for finding the chart ive been looking everywhere for this

 

The chart is based on actual tire size, not the advertised size.

 

The actual tire size is the difference. The 35" tires mentioned are probably running closer to 33s. That makes up the difference in the discrepancy noted.

 

I'm running 37's with 5:38's in my 2012 Rubicon Unlimited. Digs awesome in the sand and takes off fast at the stop light. However it's not best on mpg's , avg is 14.74 right now . I was thinking about swapping to 5:13's for a little better mileage or even 4:88's but it's hard to get away from the power that I have now.

 

Interesting looks like I just need bigger tires to be in the green! LOL I was looking for this chart and figured so based off how this jeep drives but now I see it on paper. Moving onto 35's for my 2012.