There are many forums that talk about bigger tires and regearing. A lot of different applications, off-road, rock crawling etc. I just want it to look cool. I doubt i`ll ever take it off road, much. My question is about the 2014 pentastar with auto transmission. I am new to all this and have been bitten bad by the Jeep world, but don`t have much knowledge about the logistics. My 2 door Sahara is a daily driver, I commute about 50 miles to and from work everyday on the interstate and I want to lift it with AEV 2.5 inch lift and add Goodyear Wrangler duratrac tires in 315/70 with AEV pintler 17 inch wheel. Everything I have read leads me to believe that if I add this size tire rehearing is a must. 4:10 according to some charts are ideal but then other forums talk about 4:88 which at 65-70 mph your looking at 2600 - 2800 rpms at cruising speed. Not ideal! So if someone would`t mind could you set me strait on which gear I need to use for MY application.

 

It depends on what your current ratio is. If you're 3.73, then you might be happy with it (depending on how you currently use your Jeep and what your future plans are). What I'm about to say may or may not help, but I'll give you an idea. I have a 2013 Rubi 6-speed. It came with 4.10 gears and 255/75/17's. Those tires measure about 31 inches when mounted. I did exactly what you're talking about....2.5" AEV lift and 17" Pintlers holding 35" Duratracs. The power didn't change much, but I could tell that I lost some. I drive 100 miles a day to work....mileage before and after the lift and tires would average 18-19 mpg (per the computer) - it really didn't seem to change. I'm all highway, so I'm sure I'd see a difference if I were driving in the city all the time. I always want more power and I knew that going to the bigger tires and lift wasn't gonna take me in the right direction, but I needed the ground clearance. I then started researching supercharges, but thought I'd try the Superchips Flashpaq first. It really works....woke it up really good, but I still wanted more. Like you, I keep reading a lot of posts where guys would recommend lower gears when you go to bigger tires. Studying the gear chart showed that if I went to 4.56 gears, I'd get my stock RPM's back. So I changed out my 4.10's to a 4.56.......another WOW factor! They put my RPM's right back to where I was when I was running stock! Stock tires with 4.10 gears had me at 2500 RPM's at 70mph. Going to 35's (really 34's when measured mounted) brought my RPM's down to about 2200 @ 70mph. Then when I went to 4.56 gears, my RPM's went back up to 2500 @ 70 mph. It's a lot of money to gain only 300 RPM's at 70mph, but the difference is noticeable throughout the entire RPM range. I just did this last week and haven't noticed a difference in fuel economy.....still 18-19 mpg per the computer. Maybe I shoulda gone to 4.88's, but for what I use my Jeep for (not rock crawling, but only as my DD, poking around on a muddy deer lease and pulling a fishing boat), I'm happy with just getting my stock RPM's back. I've always read that guys with automatics should go one gear ratio lower than guys with manuals....which would mean you would want 4.88's. I don't believe you could go wrong with either gear, but would highly recommend the change if you're currently running 3.73's and especially if you're running 3.21's. Good luck and just remember if you chose to do it, that the one thing you want to make sure of, is that you find the best place around to do the work! The guy installing the gears is key to them being quiet and performing they way they're supposed to. The name on the gears isn't as critical.

 

I have a similar setup, 315/70 duratracs, 2.5 lift, auto, with 3.21 gears...before you drop 2k on regearing, see how bad it is. I would definitely want more power, but I'm not going to drop another 2k on it. Just dropped 35k on a new jeep, 1500 on tires, added lift, spacers, geo brackets, lights, bumper end caps....it all adds up, and the power isn't terrible. Even in your diagram with 34" tires, the gearing is in the acceptable range for the 3.6 at least.

 

Yeah thats what I was looking for, thank you for the info. i just talked to another (Jeep) shop and they want much less for re gearing and they are very reputable, nearly 100 miles away though. 4:88 it is. How do you like the AEV lift? Firmer but not uncomfortable? I don`t mind spending the money, I just want it done right, as if it came from factory. Too new of a Jeep to go and screw it up.

 

I absolutely love the AEV Lift....and their wheels! The Duratracs are super nice as well....look more like a mud terrain, but ride like an all-terrain. That wheel and tire combo is one of the lightest you'll find - which helps in a big way!

 

I have the AEV 2.5" with AEV SAVEGRE wheels (a little heavier than the pintlers) and 315/70/17 duratracs and absolutely love me set up

 

I have yet to regear and am running 3.21 and I must say it is not near as bad as everyone says it is. In my opinion livable. However will regear to 4.56 when I get my prorock 44 for the front

 

I am looking at getting those rims do your tires rub at all ?

 

I see your Rubi is black. My Sahara 2 door is also black, do you have any pics of your Jeep lifted with your tire/wheel combo? It`d be nice to see the finished product. Thanks

 

I only have a couple....