4.56 with 32's vs. 33's

[2001XJ]

Guys,

I recently regeared to 4.56's and have BFG AT 32's on. I was wondering if I upgrade to 33's will there be a noticeable difference in power loss? I realize the tires are pretty close in size but I keep hearing how 4.56's and 33's are perfect and there is a lot of power and blah blah blah but frankly, I am not overly impressed and I have 32 which should be even better. I am not saying I don't notice it and I am not expecting a drag car but......opinions? Reason I ask is I have a buddy willing to sell me a set for pretty cheap and when my 32's run out, I was thinking of using them. Plus, I think 32's look borderline too small on my 5.5+ inches of lift

 

[mecompco]

I'm right with ya'--just installed the 4.56s and I love them with my 235x75s--I'm afraid I'm gonna miss the power when the new 33s go on. To all of you who preach the low gears, you are right on. As long as you've got OD, go as deep as you can. Sure wish I'd gone 4.88s now.

 

[RCP Phx]

I think either you really want to go fast or maybe there are some motor issues.I just went back to 32's from 33's and 4.10 gears.Its quite fun to take off from a light!

 

[ExTankerGuy]

If you have 5.5" of lift put 35s on...You WON'T regret it!!!

 

[John90XJ]

To answer your question, it will make a relatively insignificant difference. Your cruise RPM should drop about 3%, give or take a little.

 

[Barger]

I did exactly that on our TJ.

4.56 w/ 32's then went to 33's

I noticed a very small change when driving but nothing like when I had the 32's and 4.10's, been driving and wheeling it that way for several years no problems and can pass people just fine.

 

[2001XJ]

thanks for the replies so for....

RCP phx, no I have a pretty well kept engine. Only 80,000 miles on it, regular maintenance, etc. Maybe I want to just go fast Although, I do have maybe 50lbs of gear in the back plus a rigidco bumper front and rear with full size spare on the back and a conferr roof rack so that probably does slow it down a bit.

 

[2001XJ]

To answer your question, it will make a relatively insignificant difference. Your cruise RPM should drop about 3%, give or take a little.

So, this would give me a bit better MPG then....maybe? Right now I get about 15.....I am not too concerned and I know the MPG has been asked to death, I just was curious

 

[John90XJ]

So, this would give me a bit better MPG then....maybe? Right now I get about 15.....I am not too concerned and I know the MPG has been asked to death, I just was curious

Probably not. You're taking the engine a little further from its perfect operating range and the difference is really insignificant.

I run 6.5" of lift, 4.10s, 33's, a lot of armor and I get about 17.5 mpg on a long trip. My rig, fully loaded, weighs almost 5k pounds and has the drag coefficient of a brick wall. For me, the way to get some mileage back is to really focus on smooth starts, anticipating braking and carrying nothing on the roof, not even the rack.

YMMV

 

[2001XJ]

If you have 5.5" of lift put 35s on...You WON'T regret it!!!

joking, right? I guess from just a cosmetic/physical look, yeah, 35's would proabably stuff nicely with mild/moderate trimming. My C8.25 limits me to 4.56s so that combo would SUCK, not to mention I think you would be testing the limits of the stock spline axle shafts with 35s, especially on the D30

 

[2001XJ]

Probably not. You're taking the engine a little further from its perfect operating range and the difference is really insignificant.

I run 6.5" of lift, 4.10s, 33's, a lot of armor and I get about 17.5 mpg on a long trip. My rig, fully loaded, weighs almost 5k pounds and has the drag coefficient of a brick wall. For me, the way to get some mileage back is to really focus on smooth starts, anticipating braking and carrying nothing on the roof, not even the rack.

YMMV

yeah, I have noticed if you drive gingerly and anticipate, it does make a difference. Also, yes the roof rack is like a huge windsail!

 

[billyjp2]

I started with 31s on my jeep right after i regeared to 4.56s. 1st gear was like a granny gear, i moved up to a set of 33s and first gear is still a little short. With my offroad tires (34x9.5 TSLs) the jeep feels the most like what it did stock

 

[ExTankerGuy]

joking, right? I guess from just a cosmetic/physical look, yeah, 35's would proabably stuff nicely with mild/moderate trimming. My C8.25 limits me to 4.56s so that combo would SUCK, not to mention I think you would be testing the limits of the stock spline axle shafts with 35s, especially on the D30

No.

That's what I'm running...

(if I was going for looks, I would be running Thornturds!!)

 

[Barger]

Same here.
35 x 12.50 on RE 5.5 with a D30 geared 4.88 with tru-trac I haven't broken anything in the front end running this set up for a couple years now and I wheel it a lot.

 

[2001XJ]

Same here.
35 x 12.50 on RE 5.5 with a D30 geared 4.88 with tru-trac I haven't broken anything in the front end running this set up for a couple years now and I wheel it a lot.

Okay, maybe the D30 can handle the 35s.....However from a gearing perspective I was talking about running 35's WITH 4.56s since I am limited by my 8.25. I would much rather have your 4.88s but I can't

 

[2001XJ]

No.

That's what I'm running...

(if I was going for looks, I would be running Thornturds!!)

you are running 4.56s WITH 35's? Do you mean the D30 can handle the 35's as far as strength and they work well as far as flex. I can't believe 4.56's and 35 would do well, i think they do pretty decent with my 32's but not 35's!

 

[Barger]

You have manual or Auto? I'm guessing it's a 4.0

Auto would be more tolerable then manual for a daily driver. If it's mostly a trail rig I could probably live with 4.56's and 35's

 

[Ba-Riedo]

my frined has 4.56 gears and 35's

he seems to destroy his transmissions very quickly though

i run 33's on 4.56 gears and i love it

 

[selarep]

i run 32" on 3.07 and i must say... it doesnt get much worse than that. I'll do 80 on the FW at about 2100 rpms, but I get about 300 mpg to a take FW and 250 city... gonna eventually move to 4.56's next week or so.

 

[sandmcrew2]

I have 32 inch ATs on a 98 manual and just went from the 3.55s that I had swapped in from the orriginal 3.07s to 4.56s. Yeah the power is nice, but my MPG dropped from 16 in town with the 3.55s to about 14 with the 4.56s pretty consistantly. I havnt done any consistent freeway mileage since the gear swap but my freeway RPM at 80 is about 3k rpm. The nice thing though is not having to downshift to go up hills. I would reccommend 4.56s with 33s. With an auto tranny though you will probably be ok running them on 32s. Everyone said gas mileage would go up with lower gears, and like I have always found out (the hard way), everything you read on the interney needs to be taken with a grain of salt.

-Jerry