3.21 to 4.88 Difference in off road performance?

[Olean NY Jeeper]

I am saving to regear my jeep and will get it done in the next 3-4 months. I have 34s now and the next time I upgrade will either go with 35s or 37s.

How much difference will I see OFF ROAD with the 4.88s on my current set-up? Can u describe the difference? I have never wheeled a jeep with lower gearing and have only wheel with the 3.21s so I am curious what it will be like once I upgrade. Everyone tells me I will love it and I dont doubt them, but would like to know how it will effect off road capability.

Again, not interested in highway/on-road performance comments, only off road. Thanks.

[old3]

I just did this exact swap but with 32s & I have a 6m. Its awesome off road, idles over everything. First gear is just nuts, I am using 3rd in 4 lo most often but 1st will take you over big logs & rocks that would have been very abusive with the 3.21s IMO.

[tslewisz]

In additon to what those guys have said, uber-slow technical downhills are nice, too.

[Mr.ZAP]

In essence, it will make a world, nay, TWO WORLDS of difference!!!!!

[Olean NY Jeeper]

Thanks guys, I cannot wait to get them and c the difference for myself. I am up to 800 bucks saved, as soon as I get my tax return I should have the cash to get it done.

[HornetJK]

I've already got the gears sitting in the garage. My concern is more top speed. I am worried about my top RPM's when I'm doing 70 up the hwy.

[opdsgt]

Olean, the difference is night and day, cheapest power you can buy.

BLUE, I wouldn't worry too much about highway speeds. Quite tolerable.

Here's my personal experience with 4.88s. I ran this ratio with 33s last year, 35s this year, it's the perfect setup for either tire and a 6-spd.

http://www.jk-forum.com/showthread.p...88-gear-review

[joeydude]

I love it off road and in the rocks.... Say bye bye to 70 on the hwy though. I keep it under 65 now. I see a huge drop in MPG because of the higher RPMs above 65. I don't mind, I'm big and slow and everyone stares!
Running 4.88s on 315s

[NJKen]

I love it off road and in the rocks.... Say bye bye to 70 on the hwy though. I keep it under 65 now. I see a huge drop in MPG because of the higher RPMs above 65. I don't mind, I'm big and slow and everyone stares!
Running 4.88s on 315s

Ugh... Not to threadjack here but since I have my new gears already on order, why do you say "Say bye bye to 70 on the hwy though" is it strictly regarding MPG or does it not perform well in the 70-80 range

[tslewisz]

He is talking mpg.

The JK engine responds very well in the 2700-3500 rpm range.

A meaningful number of guys have regeard their daily driver 6 speeds to 5.13s with 35" tires. I ran that combo for several months. The only downside was 13 mpg at 80 mph. The performance was fantastic.

Count me in those numbers. In fact, I ran 5.13's, 6 speed, and 32" tires for a few months. My tires measure 34" (on the ground at street pressures) now. No regrets about 5.13's but I'm not interested in driving my Jeep 80 MPH.