Anyone with 6spd 4.56 and 35's
#11
Kind of off subject but I can't stand how all these new pentastar jeepers keep bashing the good ole 3.8 throughout forums. Once properly geared the 3.8 isn't bad at all. I can't wait to get 4.88's!!
#12
I'm getting 4.88 on tuesday on my 6sp. pretty sure I'll get 35s. I don't mind doin only 60 on hiway, but now, I'm thinking I should get 37s ?? thing is, with 35s, you can go with a 2.5" lift ... Saves $$ and shafts should be ok, that saves even more $.
4.88 is what I'm getting, if I ever go for 37s, it'll be able to handle it.
I think, if you can afford the 4" lift and 37" tires, you may as well go for it. Or, get a 2.5" lift and mod the body to fit 37s. Or, get a 2.5" lift, save your dshafts, put 35s on her and drive slow on the hiway! Thats what I'll do! (I think) lol
I feel for you my friend, expensive decisions!!! Thats why I'm getting 4.88, I won't regear twice, whether I like my gears or not. Go big or go home!
Good luck!
Wanna hear a good one? I'll be riding the 32s for a while too! hahaha til I can afford the 35s. Talk about slooow hiway. Maybe I'll stay on the shoulder. lol. Whatever...
4.88 is what I'm getting, if I ever go for 37s, it'll be able to handle it.
I think, if you can afford the 4" lift and 37" tires, you may as well go for it. Or, get a 2.5" lift and mod the body to fit 37s. Or, get a 2.5" lift, save your dshafts, put 35s on her and drive slow on the hiway! Thats what I'll do! (I think) lol
I feel for you my friend, expensive decisions!!! Thats why I'm getting 4.88, I won't regear twice, whether I like my gears or not. Go big or go home!
Good luck!
Wanna hear a good one? I'll be riding the 32s for a while too! hahaha til I can afford the 35s. Talk about slooow hiway. Maybe I'll stay on the shoulder. lol. Whatever...
#13
Wow, 4.88 and 32s. I hope it doesn't take long to get the 35s on there!
Lots of different opinions here. I guess a lot comes down to personal preference, geographic terrain and driving styles.
Lots of different opinions here. I guess a lot comes down to personal preference, geographic terrain and driving styles.
#14
I hope not! I don't drive it much anyway, will get 35s sooner than later, probably in the next 500 miles...don't do much hway either, i have 3.21 now and don't use 6th much except downhill -especially with the bumpers and winch- will jave to get used to not use first lol I love it.
#17
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I can't say about the 4.56 gears but my '07 JKU, 6 Speed with 4.88's on 35's does great on the Autobahn over here in Germany. I can run 100mph at right around 2900-3000 RPMs in 6th gear. I had kept the 3.21's in the axles for a long time because I was worried about the high speed mileage and revs. Once I geared down, I actually got better gas mileage and got my 6th gear back. I'm sure either the 4.56s or 4.88's will be fine. Like a previous poster said, it's just a couple hundred RPM's at 70 mph. I chose 4.88's based off of talking with Dave at Northridge, based off of my driving style and off road needs, and it has turned out a perfect balance of off and on road performance.
#18
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I can't say about the 4.56 gears but my '07 JKU, 6 Speed with 4.88's on 35's does great on the Autobahn over here in Germany. I can run 100mph at right around 2900-3000 RPMs in 6th gear. I had kept the 3.21's in the axles for a long time because I was worried about the high speed mileage and revs. Once I geared down, I actually got better gas mileage and got my 6th gear back. I'm sure either the 4.56s or 4.88's will be fine. Like a previous poster said, it's just a couple hundred RPM's at 70 mph. I chose 4.88's based off of talking with Dave at Northridge, based off of my driving style and off road needs, and it has turned out a perfect balance of off and on road performance.
So confused. Thinking about just doing 4.88. My biggest fear is regretting 4.56 after eventually adding bumpers, tire carriers etc. Etc.
Just don't want to get 12mpg on the highway.
#19
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With a 6 speed, 4.56 gears with most 35s (measure about 33.5" mounted with the weight of the JK on the ground) will run about 190 rpm less at 70 mph than 4.88s.
For anyone who lives at higher elevations, has a heavy 4 door, tows, runs heavy tires (i.e. Toyo), etc., 4.56s would be a foolish choice to save 190 rpm at 70 mph. The reason why is that with the JK engine, you need the higher rpms for more power, and at the same time, 190 rpm really isn't going to make that much of a difference in fuel economy or drivetrain longevity.
Since the OP lives at a low elevation without rolling hills, he could get away with 4.56s, but he will regret it if he ever decides to go with 37s, adds hundreds of lbs of upgrades, or moves to a higher elevation.
It is kind of funny to read posts from guys expressing gear ratio choice as something speculative or some emotional type of unknown guessing game. Please don't take this personally. I used to feel the same until I learned differently. I made the colossal mistake of installing 4.56s on my 04 TJ automatic (same 42RLE as the JK) to run 33s because I was fearfull of high rpms on the freeway in Montana. Had I understood the math and power curves of the TJ engine and the gear ratios of the automatic, I would have done 4.88s for 33s, or even done 5.13s with a D44 front axle to run 35s some day.
It isn't nebulous. At 70 mph with 35s, on a 6 speed, 4.88s will run about 190 rpm higher than 4.56s. That's it. If you spend all your time at 80 mph, then good fuel economy isn't in the realm of possibility anyway.
For anyone who lives at higher elevations, has a heavy 4 door, tows, runs heavy tires (i.e. Toyo), etc., 4.56s would be a foolish choice to save 190 rpm at 70 mph. The reason why is that with the JK engine, you need the higher rpms for more power, and at the same time, 190 rpm really isn't going to make that much of a difference in fuel economy or drivetrain longevity.
Since the OP lives at a low elevation without rolling hills, he could get away with 4.56s, but he will regret it if he ever decides to go with 37s, adds hundreds of lbs of upgrades, or moves to a higher elevation.
It is kind of funny to read posts from guys expressing gear ratio choice as something speculative or some emotional type of unknown guessing game. Please don't take this personally. I used to feel the same until I learned differently. I made the colossal mistake of installing 4.56s on my 04 TJ automatic (same 42RLE as the JK) to run 33s because I was fearfull of high rpms on the freeway in Montana. Had I understood the math and power curves of the TJ engine and the gear ratios of the automatic, I would have done 4.88s for 33s, or even done 5.13s with a D44 front axle to run 35s some day.
It isn't nebulous. At 70 mph with 35s, on a 6 speed, 4.88s will run about 190 rpm higher than 4.56s. That's it. If you spend all your time at 80 mph, then good fuel economy isn't in the realm of possibility anyway.
I completely agree with planman. I had this same issue when trying to decide between 4.56 and 4.88. After much research and advice from locally trusted offroad shops, I opted for 4.88s. It is true that the RPMs are higher. I run about 2900 rpms at 70 mph. It's right in the sweet spot for having a highly efficient gears and a VERY usable 6th gear. As I have added more weight (bumpers, etc) I have been even more pleased with my choice. Plus, it is more than sufficient should I ever decide to go to 37s. I should add this is my DD. I commute and wheel with this vehicle and have never regretted the gearing choice.
2900-3000 rpm at 100mph???? Holy cow. I have been told at around 70 mph 4.88 and 35's you are sitting around 3k.
So confused. Thinking about just doing 4.88. My biggest fear is regretting 4.56 after eventually adding bumpers, tire carriers etc. Etc.
Just don't want to get 12mpg on the highway.
So confused. Thinking about just doing 4.88. My biggest fear is regretting 4.56 after eventually adding bumpers, tire carriers etc. Etc.
Just don't want to get 12mpg on the highway.
#20
Well, 4.88 is done and I'm still running the 32s. It isn't that bad, I'm doin about 3000 at 60mph. I'm sure it'll be much better after I get my lift and 35s. The rear locker is something different to drive...anf getting used to. I love it!!!!
First gear is good for about 15'. Taking off from dead stop in 2nd isn't hard. 6th at 50mph is awesome and puts it at about 2500rpm. Talk about a useable 6th gear hahaha, I don't do much hway driving, so I can do the 55 for a while.
Stupid me, I used the $ I saved for the lift & tires and bought a bike...don't regret it, just wish I could have it all! Hahaha, I love it!
First gear is good for about 15'. Taking off from dead stop in 2nd isn't hard. 6th at 50mph is awesome and puts it at about 2500rpm. Talk about a useable 6th gear hahaha, I don't do much hway driving, so I can do the 55 for a while.
Stupid me, I used the $ I saved for the lift & tires and bought a bike...don't regret it, just wish I could have it all! Hahaha, I love it!