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  #1  
Old February 20th, 2017, 14:30
Murray_XJ Murray_XJ is offline
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'98 XJ on 33s

1998, 2 door, 5 speed, 6.5" Iron Rock long arm, 33x12.50x17s

I have looked up a number of posts about gearing, the mpg that some are getting with 33s... sorry if this is repetitive, but some of those posts get very confusing for those of us who aren't gear heads or haven't been wheeling with Jeeps for 20 years. I haven't got a full tank through the jeep yet, but in my 25 miles commute (some hills for 8 miles, 17 miles of highway at 60 mph) a round trip is sucking down a solid 1/4 tank. I'm dropping to 4th gear to deal with most hills and rpms are at about 2200 going 60. It feels sluggish though, like I'm forcing it down the road at 60 and really dragging on the hills. the engine is fresh, it was pulled from a wrecked jeep with 86k miles, fresh seals, clearances checked etc...

just looking for advice that can be understood without going to mechanics school this weekend. ;-)
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  #2  
Old February 20th, 2017, 14:41
VAhasnoWAVES VAhasnoWAVES is offline
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Re: '98 XJ on 33s

sounds about right... before i was geared in my manual i completely stopped using 5th gear. reason was that it had more power (relatively speaking of course) and got better mileage running 3k rpms in 4th gear than it did running 2k rpms in 5th gear. the difference i felt was throttle position. it chugged along around 3/4 throttle in 4th gear. but to hold 2k rpms in 5th, throttle had to be wide open. anyone that says you dont need gearing hasnt driven a geared vehicle. it is a night and day difference in performance, and drivability.


regearing puts you back into the power band and gives the motor the mechanical advantage that it lost when you installed bigger tires.
you will also like the benefit offroad as well.
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  #3  
Old February 20th, 2017, 14:51
Murray_XJ Murray_XJ is offline
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Re: '98 XJ on 33s

Thanks for the direct reply man! What gearing did you go with? It's never going to be crawled, I have it for camping, logging roads, things of that nature. I'm never going to locking it down and doing any crawling with it.

it'd be nice to improve the mpg, that's for sure. haha. Kept reading these guys still getting 18-20 on highway with 33s and I'm scratching my head.
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  #4  
Old February 20th, 2017, 14:58
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smokeyyank smokeyyank is offline
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Re: '98 XJ on 33s

4.11's would do fine. That is what I run with my 33's. Eventually I will probably go deeper to at least 4.56, but 4.11's would be solid choice for what you are looking for. If you can source them you could probably get a way with 3.73's but if your going to do it might as well do it right.
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  #5  
Old February 20th, 2017, 15:07
VAhasnoWAVES VAhasnoWAVES is offline
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Re: '98 XJ on 33s

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Originally Posted by Murray_XJ View Post
Thanks for the direct reply man! What gearing did you go with? It's never going to be crawled, I have it for camping, logging roads, things of that nature. I'm never going to locking it down and doing any crawling with it.

it'd be nice to improve the mpg, that's for sure. haha. Kept reading these guys still getting 18-20 on highway with 33s and I'm scratching my head.
5.13s with 35s... but i have a 44/9" swapped into my jeep..

4.56 would be my suggestion to you.
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  #6  
Old February 20th, 2017, 15:14
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Wayne Sihler Wayne Sihler is offline
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Re: '98 XJ on 33s

My 96 is running 4:10s w/33-12.50-15,s.RPM is about 2500 @ 70 mph,In OD.I do a lot of highway miles,set-up has been run for over 10 years.
4:56 would be my choice now
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  #7  
Old February 20th, 2017, 15:25
trippled trippled is offline
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Re: '98 XJ on 33s

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Originally Posted by Wayne Sihler View Post
My 96 is running 4:10s w/33-12.50-15,s.RPM is about 2500 @ 70 mph,In OD.I do a lot of highway miles,set-up has been run for over 10 years.
4:56 would be my choice now
Pretty much my set up. It works. Slightly more gear than stock. My speedo say 70 when actual is 65. I never go faster than that. I think I average 18 on hwy, but I gave up trying to calculate it. I had 4.56s but got 4.10 now (long story). The 4.56s really are that much better.
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  #8  
Old February 20th, 2017, 17:21
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Re: '98 XJ on 33s

I have a 5 spd as well and run 4.56's, but on 32's. Great low end response, and I can cruise 65 - 70 comfortably at 2700 rpm.

Going with 32's was my choice, because I didn't want to cut sheet metal away for negligible clearance over 33's. They stuff just fine.

Even with 32's, I love 4.56 gearing. I bet you would be fine with 33's and 4.56 gearing...
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  #9  
Old February 20th, 2017, 17:46
srb531 srb531 is offline
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Re: '98 XJ on 33s

i run 33's w/ 4.56 w/ auto. you got that 5th gear go 4.56 it will be great.
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  #10  
Old February 20th, 2017, 18:15
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beraad44 beraad44 is offline
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Re: '98 XJ on 33s

I have a 5 speed, 4.10 gears, and 35s. It sits at 2300ish at 70. I rarely downshift out of 5th on the interstate.
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  #11  
Old February 20th, 2017, 18:31
pjanda1 pjanda1 is offline
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Re: '98 XJ on 33s

I once had 33s and the stock 3.55 (for auto) gears. It worked alright, I guess. But I tossed in 4.10s and it drove 10x better. The nice thing about 4.10s is that if you are lucky, you can score a set from a stock Jeep, as there are some 4 cylinder models with 4.10s floating around.

But at 6.5" lift, why not run 35s? May as well put some 4.56 or 4.88s in there now and buy bigger tires when the time comes!

Paul
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  #12  
Old February 20th, 2017, 18:32
pjanda1 pjanda1 is offline
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Re: '98 XJ on 33s

Rats. I see now that you have a manual. If you are running stock gears, they're 3.07s! At the very least, I bet you could find a set of 3.55 axles from an auto for $300-400, and it'd drive nicer.

Paul
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  #13  
Old February 20th, 2017, 18:50
VAhasnoWAVES VAhasnoWAVES is offline
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Re: '98 XJ on 33s

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Originally Posted by pjanda1 View Post
Rats. I see now that you have a manual. If you are running stock gears, they're 3.07s! At the very least, I bet you could find a set of 3.55 axles from an auto for $300-400, and it'd drive nicer.

Paul
i did that. the gain is marginal and the money could be invested more wisely.
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  #14  
Old February 21st, 2017, 06:33
Murray_XJ Murray_XJ is offline
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Re: '98 XJ on 33s

good deal... thanks again for all of the responses. it's looking like 4.10s or 4.56s. any easy way to i.d. what the gears currently are? the guy I picked it up from said they were 4.10s, but I'm not going to bet the farm on his work so to speak.

I'd love to get to that 16-18mpg mark, as it is going to be driven a good bit. right now it's stock as far as intake, injectors, exhaust, header, etc... I'll get to that stuff a little later on. I'm trying to i.d. what's under it and biggest bang for my buck.

as for going with 35s, I just really don't have the need to. it's going to be driven a fair amount and my offroading is fairly modest.

Last edited by Murray_XJ; February 21st, 2017 at 06:39. Reason: added info
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  #15  
Old February 21st, 2017, 08:18
steveareno steveareno is offline
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Re: '98 XJ on 33s

I regeared to 4.56 for 285 (33"). Gas mileage still sucks, but acceleration is fine.
Regearing is expensive. Depending on our off-road vs. on- road use, I would recommend reducing tire size to 31" and eliminate regearing and cutting.
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