Jeep Wrangler Forum banner

1 - 20 of 59 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter #1
2012 JKU, Auto, 3.21, 33 Nitto Terra grapplers, Superchips Flashpaq, 87 Octane performance tune. The tune helped but, still sluggish on hills. Went up to my local drivetrain shop, here's basically how our convo went...

Me: I want to re-gear to 4.56.

Shop guy: Cool, what size tires are you planning on running?

Me: 35's, for half DD, half off-road.

Shop guy: 4.88!!

Me: huh?

Shop guy: You need 4.88. Trust me. I'm the gear master. This is what I do. I do at least 2 Jeeps a week. You won't be disappointed with 4.88. Don't do 4.56. 4.88, that's the way to go.....yada.

You get it. The shop is highly recommended by multiple Jeep clubs and off road shops in the area as well. So I want to trust this guy.

So, what the hell? I've read so much that 4.56 with 35's is the optimum performance pair. The wrangler is my 2nd vehicle, but I live in the big city with a lot of highway driving. Comes out only to get naked on a sunny day or go wheeling. Even if I want to go wheeling, it's at least over an hour drive to get to the closest off-road park.up to 4 hour drives. Basically the Wrangler will see a lot of highway driving as well as off-road. 70mph to get to where I need to go, see even 80 mph signs if I head West.

Where is everyone with 3.6L, 4.88, on 35's? Definitely want to hear how yours drives and if you like it. Any regrets? Any issues at 80mph?

Also the 35's I'm interested in running are either the Dick Cepek Extreme Country, or Mickey Thompson Baja MTZ's on 17X9's.
 

·
Registered
Joined
·
837 Posts
2012 JKU, Auto, 3.21, 33 Nitto Terra grapplers, Superchips Flashpaq, 87 Octane performance tune. The tune helped but, still sluggish on hills. Went up to my local drivetrain shop, here's basically how our convo went...

Me: I want to re-gear to 4.56.

Shop guy: Cool, what size tires are you planning on running?

Me: 35's, for half DD, half off-road.

Shop guy: 4.88!!

Me: huh?

Shop guy: You need 4.88. Trust me. I'm the gear master. This is what I do. I do at least 2 Jeeps a week. You won't be disappointed with 4.88. Don't do 4.56. 4.88, that's the way to go.....yada.

You get it. The shop is highly recommended by multiple Jeep clubs and off road shops in the area as well. So I want to trust this guy.

So, what the hell? I've read so much that 4.56 with 35's is the optimum performance pair. The wrangler is my 2nd vehicle, but I live in the big city with a lot of highway driving. Comes out only to get naked on a sunny day or go wheeling. Even if I want to go wheeling, it's at least over an hour drive to get to the closest off-road park.up to 4 hour drives. Basically the Wrangler will see a lot of highway driving as well as off-road. 70mph to get to where I need to go, see even 80 mph signs if I head West.

Where is everyone with 3.6L, 4.88, on 35's? Definitely want to hear how yours drives and if you like it. Any regrets? Any issues at 80mph?

Also the 35's I'm interested in running are either the Dick Cepek Extreme Country, or Mickey Thompson Baja MTZ's on 17X9's.
Honestly I have been driving in 4th gear alot. 5th for flat cruising but sometimes going 10-15 minutes down the freeway I stick it in 4th and hold. I Think it runs about 2900rpm.

5.13's with my same tires (34.2od) would put me at 2900ish at 75 mph in SIXTH.

Sounds good to me. This engine makes no torque below like 2400rpm so I would put 2550-2700 the "optimal" gearing (about 4.88's) and 2900 the "performance" gearing. Regardless of whatever the chart says.

Gear Ratio Calculator
 

·
Registered
Joined
·
230 Posts
You'll probably prefer 4.56 for the DD, and 4.88 for the trails. :)

I also have a 2012 jkur auto and regeared to 4.56 last summer. It feels good to me, but I haven't had a chance to do a lot of rock crawling yet. I pulled a trailer some in the mountains and it downshifted more than I would like, so I think if I were to do it again, I might go for 4.88. So it all depends on what you're going to do.
 

·
Registered
Joined
·
837 Posts
You'll probably prefer 4.56 for the DD, and 4.88 for the trails. :)

I also have a 2012 jkur auto and regeared to 4.56 last summer. It's feels good to me, but I haven't had a chance to do a lot of rock crawling yet. I pulled a trailer some in the mountains and it downshifted more than I would like, so I think if I were to do it again, I might go for 4.88. So it all depends on what you're going to do.
Who did the re-gear? Mind pm-ing me?
 

·
Registered
Joined
·
1,216 Posts
2012 JKU, Auto, 3.21, 33 Nitto Terra grapplers, Superchips Flashpaq, 87 Octane performance tune. The tune helped but, still sluggish on hills. Went up to my local drivetrain shop, here's basically how our convo went...

Me: I want to re-gear to 4.56.

Shop guy: Cool, what size tires are you planning on running?

Me: 35's, for half DD, half off-road.

Shop guy: 4.88!!

Me: huh?

Shop guy: You need 4.88. Trust me. I'm the gear master. This is what I do. I do at least 2 Jeeps a week. You won't be disappointed with 4.88. Don't do 4.56. 4.88, that's the way to go.....yada.

You get it. The shop is highly recommended by multiple Jeep clubs and off road shops in the area as well. So I want to trust this guy.

So, what the hell? I've read so much that 4.56 with 35's is the optimum performance pair. The wrangler is my 2nd vehicle, but I live in the big city with a lot of highway driving. Comes out only to get naked on a sunny day or
go wheeling. Even if I want to go wheeling, it's at least over an hour drive to get to the closest off-road park.up to 4 hour drives. Basically the Wrangler will see a lot of highway driving as well as off-road. 70mph to get to where I need to go, see even 80 mph signs if I head West.

Where is everyone with 3.6L, 4.88, on 35's? Definitely want to hear how yours drives and if you like it. Any regrets? Any issues at 80mph?

Also the 35's I'm interested in running are either the Dick Cepek Extreme Country, or Mickey Thompson Baja MTZ's on 17X9's.


Couple of things. 35s are not really 35". Under the load of a JKU they are tall 33s (33.5"-33.8" average at 28-30psi cold) and they get smaller over time as they wear. Do not make the very common mistake of using the on paper size to determine best gear ratio.

What are you trying to accomplish? Better 0-60? Improved low speed crawling? Towing? High altitude performance? Good long range cruise speeds and reasonable mpg?

With your Jeeps engine/trans specs I would not even think about anything higher than 4.56 unless you will be running 37" tires and do
not plan on driving far. 4.88 would be horrid for you as DD or if you need to drive at frwy speeds 70+ for extend periods of time.

I usual direct folks with the 3.6 auto trans to 4.10 gears when running under load tires sizes from 32"-33.8" (33-35 on paper) if they are looking for the
best all round drivability. 37" tires are were the 4.56 matched to the 3.6 auto trans really start to make a huge difference in day to day and trail driving.

4.88 gears have their place but it does not sound from what you posted so far that they would be the best fit for you at this time in your Jeeps life.
 

·
Registered
Joined
·
41 Posts
I'm running 4.88s and 35s on a 14 JKUR auto. Originally had 3.73s. I'm glad I did it. It'll never be a top speed demon but plenty of acceleration. I only have one issue that right now I am just dealing with. IDK if you have an auto or not, but even after a Diablo reprogram, my shift points are not where I like them. In the shift programming, the original 31s and 3.73 at high and (almost never) wide open throttle (WOT), the engine is looking for a higher vehicle speed than attainable with the 35s and 4.88 for a given gear. It gets very close to redline before I lift and it shifts. I have HP Tuners for my GMs and have seen where they now support Mopar, but just don't know if the Diablo tune is locked, etc. I pull a 1 mile long, 6% grade up and down almost every day. If I get stopped at one of the lights at the bottom, the auto holds the trans in 3rd at about 50 and that drives me crazy. I just push the gear selector over to manual and bump it into 4th until I get to the top.

If you're not too concerned about gas mileage or running 80 miles per hour, do it. It's much easier on the engine to accelerate.
 

·
Registered
Joined
·
98 Posts
I'll throw my 2¢ in here. I've been running 3.21 gears for about 2 years with 35s and a off-road shop in Dallas recently had a $1250 special for gears and I pulled the trigger. I wanted 4.56 but was talked in to 4.88.

I honestly wish I would have went with 4.56 like I planned on. Eventually yes I will go to 37s but with 35s it feels like over kill. I do a lot of highway driving and hovering around 3000 rpm on hwy speed has drained about 2-3 mpg compared to what I had with the 3.21s. Do I have to manually downshift my auto when I am against a head wind anymore...no which is nice but I honestly believe 4.56 would have done the same thing and helped with the MPG drain I now have.

Go with your gut and get the 4.56 is my opinion. 4.88 are not needed unless you plan on going to 37s like I eventually will.
 

·
Registered
Joined
·
1,559 Posts
I'll throw my 2¢ in here. I've been running 3.21 gears for about 2 years with 35s and a off-road shop in Dallas recently had a $1250 special for gears and I pulled the trigger. I wanted 4.56 but was talked in to 4.88.

I honestly wish I would have went with 4.56 like I planned on. Eventually yes I will go to 37s but with 35s it feels like over kill. I do a lot of highway driving and hovering around 3000 rpm on hwy speed has drained about 2-3 mpg compared to what I had with the 3.21s. Do I have to manually downshift my auto when I am against a head wind anymore...no which is nice but I honestly believe 4.56 would have done the same thing and helped with the MPG drain I now have.

Go with your gut and get the 4.56 is my opinion. 4.88 are not needed unless you plan on going to 37s like I eventually will.
I have 4.10 with "35's" and wish I had this "problem".
 

·
Registered
Joined
·
162 Posts
2012 JKU, Auto, 3.21, 33 Nitto Terra grapplers, Superchips Flashpaq, 87 Octane performance tune. The tune helped but, still sluggish on hills. Went up to my local drivetrain shop, here's basically how our convo went... Me: I want to re-gear to 4.56. Shop guy: Cool, what size tires are you planning on running? Me: 35's, for half DD, half off-road. Shop guy: 4.88!! Me: huh? Shop guy: You need 4.88. Trust me. I'm the gear master. This is what I do. I do at least 2 Jeeps a week. You won't be disappointed with 4.88. Don't do 4.56. 4.88, that's the way to go.....yada. You get it. The shop is highly recommended by multiple Jeep clubs and off road shops in the area as well. So I want to trust this guy. So, what the hell? I've read so much that 4.56 with 35's is the optimum performance pair. The wrangler is my 2nd vehicle, but I live in the big city with a lot of highway driving. Comes out only to get naked on a sunny day or go wheeling. Even if I want to go wheeling, it's at least over an hour drive to get to the closest off-road park.up to 4 hour drives. Basically the Wrangler will see a lot of highway driving as well as off-road. 70mph to get to where I need to go, see even 80 mph signs if I head West. Where is everyone with 3.6L, 4.88, on 35's? Definitely want to hear how yours drives and if you like it. Any regrets?


I live in Denver and have a 2012 JKUR manual and I went 5.13 with 35's and lots of armor. It's great to have 6th gear in the mountains. I usually start in 2nd but would I do it again? Yes! It's a preference so drive one with 4.88s and see if it's what you are looking for. I also plan to go 37's so I know with 37s (MT/Rs), armor, and mountains 5.13s are the right choice for me. Good luck!
 

·
Registered
Joined
·
134 Posts
The shop does 2 jeeps a week and he says you need 4.88. Listen to the man, he has put 4.56's 4.88's 5.13's into jeeps and has had feedback from all of them. If he tells you 4.88 and you decide to go with something else...it is your jeep do what you want.
When the waiter says don't order the fish, do you order the fish?
 

·
Registered
Joined
·
1,559 Posts
Yeah, it's not a problem just an observation.
Not giving you crap, just trying to make some people realize that it's always better to be too deep on gears rather than too shallow. I have to go down to 3rd sometimes to keep 65-70 up on the hills and I hate that.

It's a jk, it's not supposed to cruise at 85.

And since you will eventually be on 37's, you are in the exact right spot. Why do it twice?

Now the OP said he will only ever hit 35's. This does make 4.56 a viable option but 3 years ago I would have said the same thing and now I want 37's!

But also having 4.10 now, I can't see 4.56 as an option that would make enough difference to justify the cost. 4.88 or bust! Even on 35's for me. With 3.21, either will be a noticeable change for the better, that's for sure. But 4.88 and 33's that measure more like 32 is going to be too deep in the meantime. Hopefully that would be only temporary. That said, there is only a 7% difference between the 2 ratios.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #16
The shop does 2 jeeps a week and he says you need 4.88. Listen to the man, he has put 4.56's 4.88's 5.13's into jeeps and has had feedback from all of them. If he tells you 4.88 and you decide to go with something else...it is your jeep do what you want.
When the waiter says don't order the fish, do you order the fish?
Touche
 

·
Registered
Joined
·
21 Posts
Discussion Starter #17
Not giving you crap, just trying to make some people realize that it's always better to be too deep on gears rather than too shallow. I have to go down to 3rd sometimes to keep 65-70 up on the hills and I hate that.

It's a jk, it's not supposed to cruise at 85.

And since you will eventually be on 37's, you are in the exact right spot. Why do it twice?

Now the OP said he will only ever hit 35's. This does make 4.56 a viable option but 3 years ago I would have said the same thing and now I want 37's!

But also having 4.10 now, I can't see 4.56 as an option that would make enough difference to justify the cost. 4.88 or bust! Even on 35's for me. With 3.21, either will be a noticeable change for the better, that's for sure. But 4.88 and 33's that measure more like 32 is going to be too deep in the meantime. Hopefully that would be only temporary. That said, there is only a 7% difference between the 2 ratios.
Yes, 35's on the way. Won't be on the Terra Grapplers much longer
 

·
Registered
Joined
·
796 Posts
I have 4:88's and I get a rock steady average of 13.48 mpg...
I don't drive 75 or 80 any more...Good thing I'm retired and can drive slow.

If I were you I would get the 4:56 and use the Super Chips 87 Tune
 

·
Super Moderator
Joined
·
8,184 Posts
If most of your driving will be Highway, 4.56. That is optimal STREET (not performance) gearing. Better performance gearing for offroad is 4.88.

That said, a Jeep on 35s is fully capable of 80mph with 4.88. And if gas mileage matters that much, a Wrangler is the wrong vehicle for your purposes altogether. The 3.6 is happiest in that 2700-3000 rpm range when you need power.

And when evaluating any replies about gearing, the 3.6 (2012+) is a much different animal than the 3.8 (2007-2011).
 

·
Premium Member
Joined
·
878 Posts
And when evaluating any replies about gearing, the 3.6 (2012+) is a much different animal than the 3.8 (2007-2011).
Agreed. I've got a 3.8, 6-speed, 35s, armor, etc. and went 4.88s. It is great around town and offroad which is about 85% of my driving. On the highway it does take a little getting used to as I'm running about 2900 at 70MPH and MPG at that speed doesn't get any better than about 15 MPG. I actually get better mileage in town (most of the time) than I get on the highway if I keep my foot out of it.

If I had a 3.6L 6-speed I would definitely go 4.56. With the extra HP of the 3.6L I believe 4.56s would be great with 35s. Again this assumes a 6-speed. I have no experience with the new JK automatic.
 
1 - 20 of 59 Posts
Top