1998 4.0, AX15, 33's. Highway speeds around here are 75 - 80 M.P.H. Need to be able to handle mountain highway sections in other states as well. Please let me know actual experiences.
Thanks,
Dan
Thanks,
Dan
Should I go with 4.56 or 4.88 gears?
- Thread starter fljeeper
- Start date
4.56 is optimal for 33's with your 5-speed and 4.0 engine and it'll handle mountainous driving very well.
I have a 98 with 4:88 and 33x12.5r15's. Cooper STT Pros- I like it a lot. It is nice around town. It is a little extra lower geared for offroad and running around town, and really probably barely more rpms at the freeway than 4:56. I guess you can look at it both ways where you are saving a few rpms on the freeway getting 4:56 or for a few more rpms on the freeway, but you are getting quicker starts. That is worth it for me.
Honestly I bet you won't notice any kind of a fuel difference from 4:56 vs 4:88's I think where you will really notice a difference is coming off of a stop. I don't think you will be disappointed either way, but I am not regretting my 4:88's.
I do wheel mine almost as much as I street mine, so I am probably a 60/40 street/offroad, and running pretty aggressive A/T tires.
Just for your info, my Jeep will go 80 on the freeway with no issues with the 4:88 gears in case you are wondering.
I feel I am bias because that is what I have, but I am just giving you my experience not really trying to sell you on anything. It is all just preference, but again I don't think you will notice much difference except taking off from a stop and maybe when you are out in 4Lo. It will be a little extra lower. That is precisely why I chose it.
My old YJ had 4:56 with 33's, and I wasn't disappointed with it either, but I do like the 4:88's slightly better.
Honestly I bet you won't notice any kind of a fuel difference from 4:56 vs 4:88's I think where you will really notice a difference is coming off of a stop. I don't think you will be disappointed either way, but I am not regretting my 4:88's.
I do wheel mine almost as much as I street mine, so I am probably a 60/40 street/offroad, and running pretty aggressive A/T tires.
Just for your info, my Jeep will go 80 on the freeway with no issues with the 4:88 gears in case you are wondering.
I feel I am bias because that is what I have, but I am just giving you my experience not really trying to sell you on anything. It is all just preference, but again I don't think you will notice much difference except taking off from a stop and maybe when you are out in 4Lo. It will be a little extra lower. That is precisely why I chose it.
My old YJ had 4:56 with 33's, and I wasn't disappointed with it either, but I do like the 4:88's slightly better.
I just had gears done last week and I was between 4.10 and 4.56 on 31s. I chose 4.56 after a lot of back and forth and research. Been driving it for a week. I’m glad I opted for the lower (numerically higher) gears. RPMs do run slightly higher but I would not say too much more than if I went 4.10. I am driving a lot in 4th and 5th gear. I do go thru the first 3 gears fairly quickly. I do offroad once every month or so also another reason I went deeper. But going 4.56 does give me the option to go with 32s or 33s when I am done with these tires as well. No regrets here going deeper. If you feel like there is ANY chance of going to 35s, go with 4.88. Otherwise you will be ok with either choice.
I would go 4.88. The difference between the two is about 180 rpm.
I just had mine re-geared with 4.56 gears. 2004 5 speed manual TJ, 4.0, 33" tires, NV3500 trans. This was an upgrade from the stock 3.73 gears and the difference was noticeable. Some recommended going with 4.88 gears but even the main lead at the shop suggested 4.56 gearing. This will be a TJ driven on the highway with moderate off roading.
CO mountain driving here. my 97 4.0/ax15/33/4.56 combo was great. Plenty of pep, maintained speed, could climb hills at speed. IIRC my RPMs at speed were 2600 or 2700. I could easily, and did hit 19 mpgs pretty regularly