Oh and it's the automatic too

 

I had 3:73's straight from factory an got on average 19-22 mpg I do most of my driving highway..that was when it was stock.. Hope this helps!

 

I vote for the 373's, you'll be happier in the long run.

 

I ran my '12 JKU auto for a year and a half with 3.21's. if your plan is to leave it completely stock then I will say that the 3.21's will do the job. However, if you have the slightest plan to possibly, maybe, maybe not eventually run a larger tire than I would definitely go with the 3.73's. from what I understand its a relatively inexpensive upgrade and to change them after the fact will run you over a grand.

 

I had a '10 JK with 3.21 (3.8L V6) and as soon as you added any sort of loading to it, it got bogged down. Some weight in the back, acceleration on an incline when carrying the family, bigger tires, etc.

While the Pentastar 3.6L V6 may offer a little added oomph over the 3.8, based on personal experience I'd say go for the 3.73 without a doubt.

If your concern is fuel economy, I don't think it makes *that* much of a difference, and you will likely save much more money faster by being easier on the throttle, coasting when possible, or simply (the biggie) combining trips and not driving as much. However, when you need a little added torque for whatever application (towing, plowing, loading up the Jeep with cargo or passengers) - and I'm not even talking about big tires or bumpers - the 3.73 will be there for you.

 

Not even questionable. 3.73 no doubt.

 

I have a '12 JKU Sport, auto with 3.73's.

I have 3 friends with '12 or '13 JKU's, all with 3.21, 2 of them stick, and the other auto.

All three of my buddies have driven my Jeep (before I threw 33's on it) and all 3 preferred the 3.73 gearing. That said, I live in a hilly area.

Mileage wise, again before the 33's, one of my buddies with one of the 3.21 sticks live in the same neighborhood, and we work at the same place = we have the same drive to work. Mileage wise he gets about 11.9L/100km (19.7 MPG) while mine gets about 12.4L/100km (18.9 MPG). We drive pretty similarly, neither of us are heavy on the pedal.

Long story short, for less than 1 MPG difference, the 3.73's are the way to go IMO. The 3.21's will obviously work fine, but in terms of versatility, the 3.73 gearing just makes more sense. When I bought my JKU last year the gearing upgrade was 50 bucks...

Hope that helps. I imagine the, more or less, unanimous response to your question had you headed in that direction anyway.

Oh, and buy the way, like you, I had no intentions of going much of anywhere with mods when I bought my rig. Less than a year later I alreay have 33's on it, lift is in the mail, and now I'm saving for a bumper and winch..... just saying, never say never.

Happy Jeepin'!

 

Plowing is the main driving point behind the purchase of the Wrangler along with I don't want a plow beater as I own too many beaters. Pickup is out as most wont support plow without voiding warranty, Jeep even has maintenance schedule for plowing.

In any event I have two JKUs lined up (3.21 and 3.73) to test drive back to back this Saturday, also putting in order Saturday.

I can live with 1 MPG difference for flexibility and pep for sure, just don't want 14 MPG vs. say 17 as I drive to and from work everyday.

 

The chart below shows what mileage you can expect with the 3.73. Below 15.5 I was towing a heavy, boxy trailer.

 

Nice! I wonder how comparable if auto and 4-door?

Oops you do have a 4 door