You may actually get better mileage with the 3:73's. I have a stick and have been playing around with shift points. 2000-2200 seems to be the sweet spot for the 3.6.
With my 3;21's, it's almost impossible to keep up that rpm in 5th (legally), and 6th is useless. I have stock 32's.
That's why I'm switching to 3:73's

 

I looked for 3.73's because I knew I will install larger tires. I think it is only a $75 option to get the upgrade. You would get better mileage with a stick...im lazy and love my auto. I have a 2011 2dr. I did drive a 2dr with Mopar lift and 33's and 3.21's and was pleasantly pleased with the power of the new engine.

 

Yeah automatic for me (my other car is a stick 528i E39 3000 RPMs at 70 MPH but 27 MPG)

It seems that if a stick 3.73s no questions as 6th gear can be an issue with the 3.21 from what I gather.

Its the 4-door added weight and automatic that seems to be the harder choice, for some.

 

I had the opportunity to drive two JKUs today, 2.31 and a 3.73.
My personal observations were that the 3.73 felt smoother around town driving and had more pep as expected. But I could also see why it could consume more gas in my mind as the RPM came easy.
On the highway I had concern since it I was turning around 2,500 RPMs keep it at 70 MPM were as the 3.21 stayed a nice to me 2,000 RPMs.
Since I drive 99% highway, and yes I know it’s a Wrangler, etc. MPG is a concern to me. No off roading, no towing. Looking at it as a family daily driver, and expenses I decided on the 3.21s.
PS: have to Monday morning to change my mind.

 

Change your mind. You won't regret the 3.73.

 

I've got 26,000 miles on my 2012 in 13 months. Did a few 1,000 mile trips down interstate 95. I never once found myself wishing my RPMs were lower.

 

I have 7000 miles on my 2013 jku auto and 3.21's with 285/75-16 open country at2's and if it were stolen or totaled tomorrow I would replace it with the same. I have plenty of gidy up I live in Montana so either going up a hill or down a hill and I get great mpg it does not hunt for gears and can chirp the tires when I punch it. I am not going to be rock crawling so I wont be going to 35" tires and I think the 33" toyos look perfect on it. For the offroad camping I do it is perfect. Speed limit is here is 75 so highway travel is 75-80mph and it still gets 20mpg. Filled up today mostly back and forth to work with cold morning starts and was 18mpg. This is hand figured not computer. My odometer and speedo are spot on per two garmin gps, I used aev procal to calibrate it for the tire size increase.

 

DO NOT, I repeat, DO NOT make the same mistake I did. Order your Jeep with the 3.73 gearing. I live in pancake flat Florida and my 3.21 geared JKU had absolutely no balls on the interstate. I fixed my mistake rather quickly but it still cost me money. I now have a JKU with 3.73 gearing and I am much happier. I didn't see any mpg change going from the 3.21 to the 3.73.

 

If FloridaFeMan and me are willing to pay in excess of $1k to go down one level in gearing, it's gotta tell you something.
Get the 3:73's. You put any kind of load into that JKU, and you're gonna regret the 3:21's.

 

So are you guys saying go with 3.73s? LOL

Okay okay you will (I hope) leaving message to change to 3.73!

Thanks!