i don't think so i think if you have just the hitch and not the whole tow package like the trailer brake think then they came with 3.55 i have just the hitch and i have 3.55 i am running 33s and my mpg sucks and i have no power. i had a xj on 32s and i got around 15 mpg with plenty of power so i think it will be fine.

 

I have a 91 4.0 five speed with 31s i get 14mpg and can do 75 nicely. you will notice some acceleration decrese but no need to gear unless your going to the moutains all the time.

 

my wife's 95 had the tow hitch, tranny cooler, and light plug. so i guess if you do have all those you have the tow package.

BUT!!! if your trailer lights are running from the inside under the carpet and look like a walmart kit then i would not be inclined to think its the tow package.

 

i have a 3 inch lift, 31's and nothing really changed that much, mpg went down like 2 mpg maybe but other than that its fine. i have 3.55 gears, i do alot of up hill climbing and off roading and my tranny seems fine......runs great 160k miles 97 xj. hmmmm

 

Hmmm... so on a vehicle that typically gets less then stellar mileage as it is, a 2mpg drop isn't significant?

 

It a jeep. The abbility to be able to point and shoot, trumps MPGs. Build it to your needs, and what you want to do with it. Re gearing will improve the performance. MPGs suck and more than likely always will. I stopped chasing the gas guage a while ago.

 

My gas mileage went way down after I installed 3 inch lift 31 maxxis bighorn on cragar steel rims it seems to have plenty of power 355 gears would like to regear this summer maybe.

 

Hey xj baldy I have a 2001 xj with a rough counrty 3'' lift and 31's my gas mileage has went down quite a bit and after reading this post I decided to do some research. I don't know much at all about gear ratios but i did come across this website that pretty much lays it out for you this is the link http://www.4lo.com/calc/geartable.htm
After reading this thread I am pretty convinced I will be going to get new gears for my jeep as well. I dont like the idea of my tranny hating me either. Iraq sucks man, hang in there.

 

so from what the table says he should go to a 3.73 ratio?

Iraq does suck...I feel your pain. Once you get home we shall go for a ride! Just get home before I leave again

 

I would say yes if gas mileage is the big concern then 3.73 looks like the winner. I was thinking for myself shooting for the middle with 4.10 then if i ever do decide to upgrade I dont have to go mess with gears again.

 

For gas mileage, maybe. But trust me, take it from someone who's been down this road. If you're jumping to a 31" tire, go to 4:10's the first time. The difference between 3.55's and 3.73 is so marginal it's not even worth it. Besides, you will most likely get inch-itis at some point, and if you do and end up on a 32" or even 33" tire, you're gonna be light years ahead with 4:10's vs. 3:73's.

 

i was thinking the same thing.

 

I have a 98 with an up country package and from what I have read they came with 3.73's, but when I had the diff covers off to change the fluid the gears are marked 3.55.

 

I'm putting 31's on mine too but I have a 5spd so my gears are what a 3.05 I think it was. Kinda sucks now as it is although with this transmission I'm in 5th gear by the time I'm above 30mph. I'm actually hoping I'll be able to stay in gear a little longer, currently at 60mph my engine's rpm's are fairly high.

 

your gas mileage went "way" down because of those cragar steel rims you put on it. i had a cragar on mine for a while and compared to the aluminum mickey thompson classic lock the weight difference was crazy, two aluminum wheels are practically one of those steel wheels. weight of wheel determines gas mileage too, you could prob get 13mpg compared to 15-17. i average 18 on my xj.


2 mpg isnt that big of a deal, and if i want to get even better mileage just dont be a lead foot when it comes to the skinny pedal.....