Ok I have a 2016 jeep wrangler unlimited sport. It currently has the 3.73 gears in it and it’s sitting on 315 tires. I probably won’t go too much bigger than that except for maybe a true 35 or a small 36. But I live in very hilly western Oklahoma and I go to school in the St. Louis area and 90% of that drive is up and down hills so my current gearing won’t pull the hills without destroying my gas mileage. My mechanic has a very similar set up on his Jeep, but he is currently running 5.13 gears and recommended that I go up to 5.38 gears, when everything that I have read says that I more than likely need a 4.56 gear or 4.88 gear. It’s a pavement princess daily driver I will more than likely never take this into a crazy trail. I just want to be able to pull a hill while keeping the jeep in overdrive. Suggestions?

 

Welcome to JKF. Good group here with much knowledge & opinions. Presume yours is automatic.. this might assist in your decision: https://completeoffroad.com/images/F144165064.png

 

Yes I do have an automatic. I knew there was something I was forgetting to mention when I made the post lol. I know that every jeep is different but in your experience, do you find that the jeeps run pretty close to what the chart says?

 

Never thought about that .. I used it to decide on 4.10s for our DD 6spd '13 with 35x12.50s .. in this one they were very close.

 

I have a 2014 2 door with the automatic, 4.10 gears and Toyo 35x11.5R17 tires. It is okay but I think 4.56 would be better especially with a 4 door.

 

I've got 4.88's with 35's with the auto and no complaints. rpms are a little higher on the highway but a workhorse off road and around town its perfect.

 

I've been all over the map. If you can get used to cruising 3k rpm at highway speeds, I would suggest 4.88s for close to true 35s. I know that sounds high revving, but it's not really. You can look at it this way, you can be higher revving and have a nice drive or you can be lower revving and dealing with constant downshifts in your hills. On flat land 4.56 would be pretty ideal. Even then "perfect" can be a little aggravating to downshift in stiff headwinds. You mechanic suggesting 5.38 is absurd. If you had a 3.8L sure.....with the 3.6L it's a big L.O.L.......not unless you have 40" tires.

 

No way would I go over 4.88 with your setup. The jump from 3.73 to 4.88 is going to be huge.

 

I agree. I have 35s on mine and am leaning towards 4.56--and I do have the 3.8. But I also only have 3.21 gears right now which is waaaay too low.

 

piling on here I got a 2013 3.6L with 35" tires and 4.88 gears with automatic. Good grunt low end pulling, climbs well, highway is 70MPH at 2900rpm ( which is just alittle out of the preferred range) don't check fuel mileage that way I am not disappointed (even with a flash pac tune installed)