tjkamp

I'm running 315/70 17s with 4.10s, and a manual, to me, it is tolerable, but I really wish I could swing the budget to swap out for 4.88s.

It is a matter of opinion and taste, but I wouldn't do 35s with those gears.

RoccoV

Ok I have a 2012 JKU Sahara, 3.6, with 3.21 on 295/70/18, (34.29), Nitto Terra G2s and my wife has a 2014 JKU Sahara, again 3.6, with 3.21 on 275/70/18, (33.19), G2s. Both daily drivers. I get about 16 to 17 miles per gallon just driving normal not trying to save anything. If I try I can get 18 but I have to watch my rpms and ease off the starts. My wife, even when I drive it, gets about 18 to 19. We take her's on the long trips to save a little and when we have to do more highway driving. Hope this helps. By the way I will re-gear hopefully sometime this year to 4.56s.

shabbernigdo

2012 with the 3.6 went with 4.56's after i went to 35's . 4.10's are ok but i dont like having to mash the gas to go up hills and such. 4.56 put you in a better spot in the powerband and the engine dosent seem to have to work as hard not to mention most hills around here are not an issue in 6th.

MarwanJeeper

3.21 is sucks even with 255 tyres,t

Chewmeista

I was in this same exact situation about a month ago. I have a 2016 JKU and installed a 2.5"-3" lift and put Cooper AT3 315/75/16. I have 3.21 gears and an auto trans. At first I didnt calibrate the speedo for the larger tires and I definitely noticed a difference after the install, but it wasnt nearly as devastating as some people make it seem. After I bought a superchips flashcal to calibrate the speedo and auto shift points it made a huge difference. It honestly felt like I did a minor regearing to a higher gear.

metaldemon

I have a 2012 2dr with a six speed, and 3.21 gears. It has 315s on it. I was going to rehear, but decided not to put anymore money in to it. I have had too many electronic issue. I bought a 1994 2dr XJ to replace it.

resharp001

Everyone gets used to their own "normal", but if you're cruisin around 1800-1900 rpms @ 70mph, consider for a moment that a 3.6L would normally be around 2400-2700 rpms at that speed. I'd have to think you've thrown 5th gear out the window unless cruising downhill on the interstate with the wind behind your back. I've driven with both 35's and 37s with gears that put me as low as 2100 rpms at highway speeds. I can't imagine being any lower than that. Gearing is one of those things that you get use to as your normal, but as soon as you do it you see the light and wonder why you didn't address it sooner.

kejtar

Probably the best phrased comment regarding "3.23's being ok with big tires". Where is the like button when you need one?

resharp001

I know it sucks to spend money on re-gearing. Most people don't realize the downside of the stock gearing until they want bigger tires.....at which time the cash outlay for wheels and tires makes an additional outlay of ~$1500 a harder pill to swallow. I would only say this......if it's a vehicle you plan to keep for a long time, it's money well spent. Is it sexy? Nope, not at all. Will people look at your jeep and realize you've done anything different? Surely not, but it will have a direct and immediate effect on your driving experience. I'm not suggesting you'd HAVE to regear in order to throw larger tires on, but you'll definitely want to plan on it at some point.

tarpon4me

With my stock gears it was horrible. Definitely didn't have a 5th gear. Mine is a 2014 manual 2 door for reference.... I dropped to about 15MPG from 20+ MPG on the stock tires. I went with 4.56 gears and with 35's it's about perfect for my application which is a mix of highway and offroad. I do highway runs at a brisk 65 MPH or less for optimal efficiency, which is around 17-18 MPG depending on how flat the road is. Off road the jeep pulls very well with plenty of power down low where I want it. In your case, 4.10 would probably be perfect. You should get closer to 19 give or take depending on how you drive. A buddy just went to 35's on his 4 door with the factory Rubicon 4.10 gears and that's where he's at if he stays off the skinny peddle.