I am very happy with mine. I have a '12 auto tranny. I do lots of highway driving between 55-65mph. Great MPGs.

 

In the city, the 3.73 and 4.10 wouldn't necessarily return lower MPG's. With the 3.21's sometimes you have to mash it just to get it to move and that kills fuel economy.

 

I just bought my 2012 JK after having test driven several on the lot, both with 3.21s and 3.73s. I found that even with the larger 255/75R17 tires that came with the S package on my sport, first gear in my manual transmission is plenty deep to get my Jeep going with the 3.21 gears. I'll cruise the freeway in town at 55 (speed cameras everywhere) in 5th gear just fine. When I get out of town and get up to 70-75 in 6th gear and cruise with no problems. With the 3.73s, I felt that first gear wrapped out a little too quickly for my tastes but starting out in second gear wasn't going to cut it. The 3.73's felt a little unbalanced because of that. Now, I think the ideal gear for the size tire I have is probably a 3.31 or even a 3.54 but I'm not going to be able to get that from the factory and I'm sure as hell not going to pay to do that minor of a swap. Given that this Jeep is going to be my daily driver for the next 4-5 years, I decided that the 3.21s were for me.


My crawl ratio is around 39:1 which is fine for light to moderate trail riding, which I do plan on doing while I daily drive this Jeep. I plan on sticking with stock size tires for the first several years. Having driven several stock Jeeps over the years, I know that this setup will be fine for light duty work.

I know I'm not going to do any kind of serious technical rock crawling in this Jeep for quite a while. There just isn't that much of it available anywhere near me. When I want to do that in this JK I'm going to be doing a lot of work to it to get it ready to do that. That kind of work is going to involve at least swapping out the front axle assembly entirely. I may even swap out both axles as well. If I just do the front axle, I'm still going to have to modify the rear axle. I'll swap out the gears to mach and replace the carrier with a full locker so whether I have 3.21s or 3.73s won't make one iota of difference. I'll just buy the new front axle with the gears I want and drop the $1500 on a gear/locker swap in the rear. Or, if the budget allows, I'll just go ahead and drop in the matched D60's and build them the way I want so I can run 40's or bigger without worrying about pushing a marginal axle.

So yeah, the 3.21s are fine for now. Exactly what I need. When the Jeep is no longer my DD, that will change.

 

I think folks get a little lost in the weeds on this.

IMO, the 3.21s are fine. Your jeep will go in the direction you point it. But the 3.73s will in all respects be better, except for a marginal gas mileage impact.

So the issue isn't the 3.21s are awful and the 3.73s/4.10s are awesome, it's just that for $100 or whatever it costs to order 3.73s from the factory, almost everybody would be better off ordering the 3.73s.

 

I ordered 3.73's on a 2013 JKU auto. But I fought long and hard all last year on behalf of 3.21's with the new 5 speed auto's. I think 3.55's or so would be perfect....and I ONLY ordered 3.73's for the increased "Chrysler approved" tow ratings. I test drove both ratios back to back last year in identical Sahara JKU's. The 3.21's were fine.

 

....and I ONLY ordered 3.73's for the increased "Chrysler approved" tow ratings.

Panther, explain this. I looked on Jeep's site and it doesn't say anything about gear ratios under the towing information.

 

While this may have been true on pre 2012 this is just not the case with 2012+. The new auto is geared lower and the 3.6 has loads more power to take advantage of the 3.21 while getting better mpg. There are special applications. If you live in the mountains or plan to tow.If you are going with over 33" tires then sure 3.73 or even more would be ideal. For most people as an all around DD / occasional wheeler with 33" or smaller the 3.21 is a better option on the 2012+

 

For most people as an all around DD / occasional wheeler with 33" or smaller the 3.21 is a better option on the 2012+

If you value a marginal increase in mpgs over an increase in power, then yes. Most jeepers don't fit in that category or they would've bought Priuses or Accords. I'd trade one mpg for some more zip off the line and torquey-ness around the trails, and think most folks that drive jeeps would.

For example:

On my end I'll be using it for a daily commute into Manhattan and MPG's although not that important to me should be somewhat reasonable, so the 3.21's are fine for now. Would I prefer 3.73's? Yes, but I'll probably wind up changing them down the line anyway. So for now, 3.21's will do the job.

I'd say this is the view of most folks who drive jeeps with 3.21s. They're fine, but they'd rather have 3.73s.

 

It all depends on what you are planning to use the Jeep for. On my end I'll be using it for a daily commute into Manhattan and MPG's although not that important to me should be somewhat reasonable, so the 3.21's are fine for now. Would I prefer 3.73's? Yes, but I'll probably wind up changing them down the line anyway. So for now, 3.21's will do the job.

 

Thanks!

 

My wife and I just got his and hers Jeeps as a late wedding present to ourselves. She got 2012 JKU with the 3.21 gears and mine is a 2013 with 3.73 (Wife wanted the one on the lot with tires/wheels already installed and I opted to wait two weeks). Needless to say, she get's slightly better gas mileage and with the new 3.6, can't really tell that much difference in drivability on highway or beach in 4 wheel drive. May be a different story when we take them to Concan in November to run the rocky/hilly Jeep trails.

 

Being a new wrangler ower there was a lot of not knowing when it comes to gears. Bought mine almost a year ago w 3.21s (which i had no idea) added 33s 4 mths after I purchased it. If I would have known gears mattered with adding mods then I would've sesarched for 3.73 on lots. Still happyy with my 3.21 but for $100 more 3.73 is a no brainer.

 

Wish I'd'a Known

MTH has convinced me, and I do a lot of highway miles on my way to the trails.

Since I tow with a manual and plan to upgrade tire size slightly as stockers wear out, I wish I'd camped on this site a few months before I ordered my 2012.

Nevertheless, consider me very satisfied with my 3.21s. I prefer low r's for cruising, but not necessarily for improved economy. I've found there's more to (marginally, agreed) improved fuel mileage than just low r's.
If I want lower gearing I can just downshift. If I want a higher gear than sixth, it can only easily come from the differential(s).
I haven't yet had to ride the clutch through any rock gardens.

How big a deal is aftermarket regearing?

 

How big a deal is aftermarket regearing?

About $1200 to $2000.

 

If getting tire upgrades I think 3.73 would be best for 33s, considering u lose the extra mpg anyway, so why not get it back with power

 

Hi

As a nature photographer I want 4x4 that is mostly in the wintertime with snow because in Sweden it is not legal to drive offroad to protect the enviroment. We destroy the enviroment by 100% with asphalt instead and drive on that and that is legal and nobody complain :facepalm:

Anyway my first 4x4, very similar to Wrangler was a "baby wrangler" a suzuki Jimny 4x4 1.3 liter engine, with low gear and ladder chassi. Very good in terrain and very low geared. Not so very good at highway, maybe little bit loud. But I avoid highway, I want to be in the nature and drive mostly my 4x4 in nature in small roads and enjoy the nature and sounds.

Had it for 12 year.

Bought the 2012 Jeep Sahara Wrangler 2 door with 3.21 automatic. I was used to the suzuki 1.3 liter engine and now got a 3.6 liter engine, I felt it was little bit scary with the wrangler with so much power, I had to drive carefully. It was like a sportcar.

anyway, I went out on a camping with totally 4 adults in a 2 door with alot of camping gear and all was amased with the power it has.

A crapy film from that trip

Camping with my friends and my 2012, 2 door Jeep Wrangler - YouTube

After that trip I found out maybe I should have bought the unlimited instead for more space. Me and my girlfriend tried a unlimited with 3.73, we both noticed that we didnt liked the sound from the engine. My girlfriend sad that do not buy a 3.73 wrangler because they sounds bad and load and noisy.

It could be a bad motor? but we both noticed it was more pleasing for the ear to drive my 3.21 against the unlimited with 3.73 gearing. I have not read that anyone have noticed this on the internet, maybe bad motor or nobody cares about more noice.

It was ment that I got a 3.73 wrangler (wrong from the factory) but I got a discount on about 5400 dollar for my 3.21 so I took it.

Then I read a lot on the internet and all say everyone should have at least 3.73. I check them up, and many of them have never tried a 3.21 with the pentastar engine.

Anyway, got about 5400 dollar in discount for the 3.21 and got got huge scary power compared to my former suzuki with 82 hp and 1.3 engine.

I drive with 255/70/18 stock tires and the petrol cost 2x here in in Europe.

A 3.6 liter engine is very huge buy European standard.

Best regards from Sweden

Omar Brännström

 

^^^ Cool video Omar, but my brain hurts after watching it lol

 

Cool to see some Jeep love from Sweeden.

 

2010 2dr manual w/ 31" SRA and 3.21. Does great on the highways which is 80% of what I do. Regularly get 22.3 MPG. As you can see in my sig, that will change here real soon. I've done moderate/medium trails with it and wished it was slightly higher in gearing, but not by much. Overall I'd say 3.21 with a 31" or 32" would be maximum.

 

I have been waiting for a Diesel Wrangler for so long, that I'm thinking about going to Mexico or Italy to buy one. My plan is to use it for plowing mostly. Plowing is a winter sport for me. I also want a diesel for range as I like to explore. I have considered buying one and not registering it here in the US but would prefer to register it.

I've also thought about doing an engine swap with a 3.0 liter VM diesel motor. I suspect there are plenty of people that would gladly buy a brand new pulled 3.6l motor with zero miles on it. That would give me a diesel that was registered, with a simple fuel type change when the time came to renew the registeration.

So given the torque of a diesel, I wonder what size tire it could handle with 3.21 gear and 3.73 gears. I have 3.73's in my Silverado.

I was leaning towards a mild lift of 3" or perhaps leaving it stock. A Rubicon forces me into 3.73 gears and gives a beefier front axle.

I need locking differentials and would prefer not to have to install those. While a 3.21 would give me what I wanted most, best fuel economy. If I registered it, it would would get a lot of on road use.

So my feeling is, getting a Sahara, with 3.21 gears, locking differentials, popping in a diesel, throwing away the rear seat and adding a second fuel tank for a counterweight to a plow, and this would give me what I wanted. Long range, good fuel economy, and a maneuverable plow rig that would allow me to make more money while having a blast playing in the snow.

I am curious as to what gearing is offered in Wranglers overseas with the diesel option.

 

Looks like 90% of the 3.21 owners are happy with it.I am not surprised but I am sure some are.

 

I am quite surpirsed, but chances are I belong to the few Jeep owners that tow a camper.

If you value a marginal increase in mpgs over an increase in power, then yes. Most jeepers don't fit in that category or they would've bought Priuses or Accords. I'd trade one mpg for some more zip off the line and torquey-ness around the trails, and think most folks that drive jeeps would.

I would have to agree on this one, you don't buy a cinder block on wheels to complain about 1 MPG, but I will admit I am extreemly surprised on the mileage I get with my '12 with the 3.21, but I am a performance oriented driver, I drive my Jeep like I drive my Mini. I'll take the performance over the mileage anyday.

If your Jeep it just a cool family SUV which they are now for sure, then the 3.21 will suite your needs I guess.

I still think Jeep should make the 3.73 the standard to cater to the majority of Jeep owners that are not too concerned with MPG, and have the 3.21 available to the guy or girl that just wants a Jeep for a daily driver.

I got about 8MPG in my '80 CJ and loved every mile.

 

I am quite surpirsed, but chances are I belong to the few Jeep owners that tow a camper.



I would have to agree on this one, you don't buy a cinder block on wheels to complain about 1 MPG, but I will admit I am extreemly surprised on the mileage I get with my '12 with the 3.21, but I am a performance oriented driver, I drive my Jeep like I drive my Mini. I'll take the performance over the mileage anyday.

If your Jeep it just a cool family SUV which they are now for sure, then the 3.21 will suite your needs I guess.

I still think Jeep should make the 3.73 the standard to cater to the majority of Jeep owners that are not too concerned with MPG, and have the 3.21 available to the guy or girl that just wants a Jeep for a daily driver.

I got about 8MPG in my '80 CJ and loved every mile.

I'd say most "new" buyers use them as SUV's and daily drivers. This site is full of wheelers, but most new Wranglers sold don't ever hit the trails (not on a regular basis anyway).

Luxury auto JKUs are the big sellers now.

They are doing what you say, but I think you have the roles reversed. I bet there are a lot more JK mpg threads than TJ mpg threads.

Than again..."concern" is in the eye of the beholder. Not a big diff between 20 and 21 mpg. Nor is there a big diff between 14 and 15 mpg. But I do think there people who are buying them as SUV's hoping to get +20mpg on the highway...and don't want to see 17mpg. At that point...every extra MPG does matter (to some).

 

Zero complaints here, and my commute route has its share of hills, curves, combinations thereof and such. Since it's my driver, anything that will better mileage is appreciated also.

Now, if I were lifting it and slapping on some giant tires.....

 

Not too many folks gonna toss down 25 or 35k for a Jeep then take it out and thrash it on the rocks.Yes some do but most cant afford to.

My JK is my DD and I have always had a Jeep above all else because of where I live the roads are terrible in the winter.Then comes in to play my other needs. I hunt , fish and also enjoy some trail rides so the Jeep fills all of those needs. But above all else it is my DD and I can not afford to thrash it. Once its paid for and I am able to replace it if it gets damaged then maybe I might give it hell on the trail. More and more people are attracted to JK and JKU because they are an affordable SUV that does get better fuel milage than most other suvs so there you have a popular 3.21 ratio that most are happy with. If I wanted a real rock buggy or beast to thrash on it would be a full caged small block chevy powered CJ8 riding on D60s on 40s. But for what I need the JK with 3.21 is perfect.

 

Luxury auto JKUs are the big sellers now.

I agree, I see alot more "Soccer Moms" (My wife included) Driving around in JKUs. I have almost always had a Jeep and wanted a JKU since we had kids and when I herd of the new interior and engine I waited for the 2012.

Mine is a daily driver with an scattered offroad adventure and its our camper hauler in the summer. JKU is the perfect ballance of sport and luxury, it rides great, looks good, and can go lots of places. I am just very unhappy with the 3.21, but I have the solution on my work bench at home.

I tested a '09 before the '12 and wow what a differance, even with the 3.21.

I have a problem with keeping things stock, everything I own has been modified, I guess thats the gear head in me....always tying to get that little extra out of my cars.

 

I called Chrysler about the tow rating on my 2013 Wrangler Sport 2 dr. Was told engineers said 1000k max with the auto and 3.21s.

That is part of the problem with Jeep. They need to get their act together. Their spec sheet says 2000 pounds. The owners manual does not even list a tow rating for the 3.6 with 3.21's and an auto. When I called last year, I was told such a combo did not exist.

 

I agree about the growing new bread of JK owner that really appreciate the road qualities of the newer Wranglers. We test drove a new Jeep in the 1990's and my wife said, "This drives like a lawn tractor!"

Not so anymore. We rented a 2012 Sahara in Spokane this summer and put 2830 miles on it in 13 days going thru Glacier Nat Park, Canada, Montana, Idaho and Washington. Twice we were 65 miles off the pavement and once 40 miles, including an aborted attempt to cross the 121 mile Nez Perse pass on dirt/gravel before it was officially open for the season.

Net result: She said, "I love this car and want to have one for myself". Highway performance and passenger comfort at 70 certainly weren't like our Honda, but she actually said, 'I'll miss you"........to her rental car!!! We purchased our 2012 JK just 5 weeks later. It's for her DD, she turned 61 yesterday.

Point being after 2800 miles:
1. We were dazzled by the off road capability of a stock Sahara JKU with 3.21s.
2. We were completed amazed how civilized yet fun a Wrangler is for just driving around in.

I have to share a photo of this rental in Canada. As an aside, my lifetime biggest Jeep adventure will probably always be the time I got into the Jeep just three seconds before the bear, and shot this photo back thru the side window. The last photo is my new rig, Flame Red and purchased in honor of the most depriciated of all Jeep Wranglers, the lowly rental car. But it had a big impact on us, getting us into real adventure and out alive, 3.21's and all.

 

Even the bear likes the jeep

 

Cool picture of the bear and the Jeep.

 

That is Not "a Bear"...

...THAT is a GRIZZLY!

 

...THAT is a GRIZZLY!

Yes. I understand that when they come up at you on two feet, as this one did, it's not a good sign. Plus, when I jumped in the car, I still had the window down. If he had gone to full acceleration from the first he would have had me. It's not in the picture, but his claws were 4 inches long.

I'll be shopping for either lockers or perhaps Eaton True-locks for our new Jeep some day. But the Jeep gear I will always probably most remember and appreciate, was the Freedom Top and the safety glass of that stock Sahara...... as Mr. Grizzly licked his chops and stared down at me, from 4 feet away.

When she settled down a bit, my wife said, "So honey, was that what you meant when you said "It's a Jeep Thing............"