I just picked up a new 2012 jku. it has the new motor, but stock 3.21 gears. I want to do about a 2" lift with 33's or 305 70's. Will I be ok with the 3.21 or will I need to up grade? This will see more on road use then off. I sold my 08 which was on 35's with a 3" lift. looking to be a milder set up on this as it will be more of a daily driver

 

I'm rolling 33's and 3.21's in a 3.8L with a 6 speed. While I'd like a little more get up and go its certainly not undriveable. With the new 2012 I honestly don't think you'd actually feel much difference over stock.

 

Ok cool that's encouraging. Down the road if like to put some rubi axels underneath or something similar.

 

I have the same, and I agree. With the 3.6 you will still be miles ahead of the 3.8 using this
setup.

 

I have 305/70/16 duratracs 3.21's and in a 2012 6 speed. It wasn't too bad when I first started off like this but as I add more weight I can feel it getting worse. Not sure how much you drive day to day but it's tolerable for now but 6th gear is all but useless unless I'm going about 80mph on completely flat highway. Eventually I'm going to regear when I get the money together.

 

Will be driving everyday. I have the 5 speed auto

 

I meant how much as in how far is your drive. I work like 5 miles away and there's only a few lights and small hills. It takes a lot more to get my jeep rolling now than it did when I had the 225/75/16's on it and my gas mileage is now around 14-15mpg when I'm all local. Acceleration once I'm rolling is fine but it's that initial start that really sucks.

 

I only have lto go about a mile to work. But when the wife goes its about 10 miles. Highway.

 

I have a 2012 Unlimited Sport with the 6spd and 3.21 gears and run heavy 33's and there is a noticeable difference in acceleration but overall it's still very powerful.... and 6th gear is meant for rolling downhill at 80mph...