hetkind

The STOCK tire size on our 08 Sahara with 3.21 gears are 265/70R18 or 32" tires...right now we are running 245/75R17 at 30.6" Blizzacks and all is well. Personally, I would rather have the rubicon axles with the 4.10 gears.

Howard

bobbyspaghetti

I run 265/75R16 Fierce attitude MT's on stock alloy rims (2007 had 16" alloy rim upgrades) I also have the manual and it is an unlimited. I live in northern BC and there are some pretty good hills around here. I cannot do 100 km/h in 6th gear if there is any incline at all, or wind. I have a 2.5" teraflex coil lift so I am a little less aerodynamic then stock. I absolutely hate having to shift into 5th 4th (and sometimes i debate 3rd) gear just to make it up a hill. These tires are only like 31" actual measure. I decided to go this size so I did not have to regear. I now plan to go with 285/75R16 or pizza cutter 255/85R16 and plan to regear to 4.88s as I still dont want to go 35"s. I test drove a 2 door rubicon and found that with their ~32" tires and 4.10s that it was no screaming hell, which is part of why I thought 4.88's and not 4.56, the deciding factor was a discussion with a member who runs 4.88s with 33's and of course Dave at Northridge said go 4.88's. All I know is that with my 31" tires on a 6 speed unlimited on hills I constantly feel like I am towing a heavy trailer and all of the 14rwhp of the 3.8L just can't do it. However offroad I actually dont find it that bad in 4low even with the non rubicon rock crawler transfer case. Hope this helps at all.

CrazyShadow

I run 285/70/17 ( 33X11.5 ) on stock wheel, I barely noticed performance change, I had stock 255/75/17 before.

my 33s are BFG mud KM2 on 2dr JK manual 3.21s

adicus8

I have an x model as well, with a 3.5 inch lift and 285/75/16 tires which are baisically 33s. My jeep is fine, but a bit sluggish. I am putting an air intake on it to pep it up a bit and mabye a superchip down the road.

Mr Hobbit

I'm running the same setup as adicus in a six speed. I'm also up at altitude (Denver). I've found mine pretty laggy. I'm in 4th and sometimes 3rd for high altitude passes.

jeep4president

I put 33" BFG A/T's on my '07 X, after I bought it with the 3.21 gears. I hated the loss of power, having to downshift to 5th or 4th on a long easy grade. I thought that would just be my lot in life as I did so much driving to work that I didn't want to lose the mpg by regearing. Then I joined this forum and read about the superchips flashpaq. I got it and noticed a difference. Then I put on a flowmaster 40 and bam - I am grinning ear to ear. The combination of both is awesome. It's obviously not a supercharger, but I actually enjoyed my 2-day road trip from Monterey to San Felipe in the Baja and was very happy how it performed in the desert too. Now I am so excited with the new feel of the power increase from the computer and muffler (no technical data to support, but I don't really care about that), I've gone power crazy . Next check will be the CAI!

bearstylez

Do you think you could run 35's with this set-up...the chip and muff?

wayoflife

sure you can do it but you will feel significant power loss. for some it's tollerable - don't know if it would be for me.

Yeller Sled

Im running 35s and stock 321s i do find it needs a bit more but does ok for now

IcyFridge

I run 33s with a 3.21 six speed and I have no problems. I can hold 65+ on the highway in 6th, unless theres a head wind or incline. Most of the time I just run in 5th gear unless I'm above 70 mph.

The real problem comes with mountain highways, where a lot of shifting has to be done. I think the 3.21s are just fine and my jeep scoots around quickly in the city. Getting about 17mpg overall.

Would I prefer better gears? Yeah.... WITH 35s. 33s are not that much bigger than stock and 3.21s are just fine.