I am new to the forum so please bear with me. My question is this:

I have a 2.5" TeraFlex lift kit with 18" wheels and 32" tires. I am currently running with 3.73's. Do I need to upgrade to 5.13's? I've noticed that my performance has dropped especially on the highway. I'm trying to figure out if re-gearing is the way to go, or if I should invest in some performance mods such as cold-air intake & performance exhaust instead. Maybe both??
My Jeep is a daily driver, and I want good off road capabilites as well. Is anyone else getting 12 miles to the gallon out of their Jeeps after lifting it??
Any suggestions are appreciated. I did check out the newbie questions page and I didn't see anything listed for tires under 35", so that's why I am posting here.
Thanks!

 

you dont want 5.13 with 32" tires, maybe something more like 35". i would say get ahold of some oem 4.10s someone pulled out. also gear swaps arent the cheapest on labor. you want to make sure you pick a good ratio for the size tires you have or plan on maybe someday having.

 

Unfortunately, it is very common. Auto's are under-geared straight from the factory.

Do you have any plans on increasing the tire size?

My personal opinion -
If you are staying with 32's, turn O/D off, get a Flashpaq and call it a day.
If you are going up to 35's, that is the time to re-gear. ($1000-$1500 is a lot to pay to re-gear for a stock tire size...)

(search around a bit for more input, but the general consensus is that engine mods other than the Flashpaq are not worth the money- unless you are just looking for a 'better sound)...)

 

My Jeep has 32's, a 6-speed, and 5.13's and I love it. But:

- If my driving entails Interstate, I drive (or ride) something else. Heck, my Jeep doesn't even have cruise control.

- I don't keep track of fuel mileage.

Originally, mine had 3.21's which sucked everywhere except trail riding in 4 low.

 

I think 5.13s would be a little much. I would imagine your RPMs with 5.13s and 32" tires would be close if not over 3000 and your mpgs would be crap. Most of us on 35s are running about 23-2400 RPM @ 70 mph on the interstate.

If anything, get the superchip and try that. Much cheaper than new gears. That being said, after, all the jeep is a box on wheels and not a sports car.

If you really want new gears, then I would wait and see if you want to get bigger tires so your not spending all your money twice !

 

2603 for 32's, 5.13's and an auto. Not bad at all.

 

to comfort you. i have 3.73's and 32's and i get 13 to 13.5mpg

 

I'm not upgrading my tire size anytime soon as I just got my Jeep in November, but, I plan to upgrade eventually when I need new tires.
Will the Flashpaq void my factory warrenty?

 

Is anyone out there running 5.13's with 32" tires? Just curious how much of an improvment it would make. I could always upgrade my tires after the gear upgrade. According to the chart, 5.13's seem to work well with the 32's and gives me better on and off road capabilites. Hearing it from someone who actually has this set up would make me more apt to do it though.

 

You have actually measured your tires at 32"? Or you're saying they are 32 because the mfg says they are? Plug in the actual height when you use that chart, as they could be 1-1.5" shorter than what you think...


Here are some numbers from when I was checking O/D Off rpm's. The only downside for me was towing on the freeway. Too much gear to tow my boat on that tire size...


Auto - 5.13's - 295/75/16 Terra's (32" actual height)

MPH O/D off O/D on
40 - 2150
45 - 2500
50 - 2700
55 - 3000
60 - 3250 - 2200
65 - 3500 - 2400
70 - 3800 - 2600


Now that I'm on 35's, I wish I had a Rubi so I could have gone with 5.38's