Gear question, 3.21 to 4.56 on the 3.6L - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-26-2013, 10:52 AM   #1
Jeeper
 
New2012JEEP's Avatar
 
Join Date: Dec 2011
Location: NB, FL
Posts: 1,418
Anyone running duratrac 33" tires (believe mine are truly 32.5") with 4.56 gears? I was looking to regear to 3.73, but was suggested to go to 4.56 for my setup. I do occasional towing of a 2100lb boat/trailer setup weekends mainly, and not very far. This is also my daily driver, average stop and go traffic, and normally 50-70mph.

Will these be too drastic a change?

I was told mpg would actually increase, just hard to believe. Any pros or cons going 3.21 to 4.56?

Thanks everyone

I was also told the 3.6L was best candidate for it due to engine specs vs the 3.8L

I have the auto tranny

__________________
2014 JKUS
OME 2" HD, MB 72 15's on 33" Goodyear DT's, Synergy Metal Grab Handles, ORO Center License Plate Bracket with LED Lights, Vector Offroad LPD, TrukLite Heads
New2012JEEP is offline   Quote
Old 07-26-2013, 11:12 AM   #2
Jeeper
 
JKWrangler2012's Avatar
 
Join Date: Oct 2011
Location: Greensburg
Posts: 600
I don't see your transmission noted in this therd or your profile.

I've made the switch from 3.21 to 4.56. I have the six speed and "35" inch duratracs (33.9" mounted) I find this set up to be ideal. At 70 mph, I'm just a hair over 2500 rpm.

That said, gas milage certainly did not increase. If my set up was with the auto or smaller tires the rpm would be higher at any given speed.

JKWrangler2012 is offline   Quote
Old 07-26-2013, 11:16 AM   #3
Jeeper
 
New2012JEEP's Avatar
 
Join Date: Dec 2011
Location: NB, FL
Posts: 1,418
Quote:
Originally Posted by JKWrangler2012 View Post
I don't see your transmission noted in this therd or your profile.

I've made the switch from 3.21 to 4.56. I have the six speed and "35" inch duratracs (33.9" mounted) I find this set up to be ideal. At 70 mph, I'm just a hair over 2500 rpm.

That said, gas milage certainly did not increase. If my set up was with the auto or smaller tires the rpm would be higher at any given speed.
Hey thanks, it is automatic, and 2 door. They said at 70 I would be at about 2200 rpms.
__________________
2014 JKUS
OME 2" HD, MB 72 15's on 33" Goodyear DT's, Synergy Metal Grab Handles, ORO Center License Plate Bracket with LED Lights, Vector Offroad LPD, TrukLite Heads
New2012JEEP is offline   Quote
Old 07-26-2013, 11:32 AM   #4
Jeeper
 
JKWrangler2012's Avatar
 
Join Date: Oct 2011
Location: Greensburg
Posts: 600
With 4.56? They lied! 3.6 auto with 4.56 and 33" will be over 2600 rpm at 70 mph
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	3114
Size:	109.7 KB
ID:	277697  
JKWrangler2012 is offline   Quote
Old 07-26-2013, 11:37 AM   #5
Jeeper
 
Join Date: Jul 2013
Posts: 24
I am running 35" DT with a 2.5 inch lift and recalibrated on 3.73's. I am really happy with the performance and gas mileage. Have not really been on the highway that much to determine rpm ranges at 70 mph, but a good mix of city and rural road driving I have been getting 18.6 mph both calc by the computer and hand through 3 tanks of gas. I am heading up to Montauk this weekend so will have plenty of highway miles to see rpm ranges.
thunderdan11 is offline   Quote
Old 07-26-2013, 11:37 AM   #6
yeah,,,, im that good

5-Year WF Supporting Member
 
panthermark's Avatar
 
Join Date: Aug 2011
Location: Chicago-land
Posts: 10,235
Images: 13
4.56's seem really aggressive for 33's....especially on a 2 door auto.

3.73's and 4.10's would be fine. But I guess if you are going to make the jump, you might as well make it worth your while. You could easily run 35's, and even 37's with 4.56's on a +2012 auto.
__________________
2013 Sahara Unlimited
Billet - Auto - 3.73 - Connectivity - Painted Hardtop - LSD - Remote Start - Saddle Leather - Side Airbags

I may mall crawl...but I look good doing it.....
panthermark is online now   Quote
Old 07-26-2013, 11:43 AM   #7
Jeeper
 
New2012JEEP's Avatar
 
Join Date: Dec 2011
Location: NB, FL
Posts: 1,418
Quote:
Originally Posted by JKWrangler2012 View Post
With 4.56? They lied! 3.6 auto with 4.56 and 33" will be over 2600 rpm at 70 mph
I'm not liking the sound and look of that. I wonder if 4.10 is better. I don't like the idea of higher rpms on 6+ cylinder engines, doesn't bother me on smaller engines
__________________
2014 JKUS
OME 2" HD, MB 72 15's on 33" Goodyear DT's, Synergy Metal Grab Handles, ORO Center License Plate Bracket with LED Lights, Vector Offroad LPD, TrukLite Heads
New2012JEEP is offline   Quote
Old 07-26-2013, 11:57 AM   #8
Jeeper
 
JeepHerz's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 3,032
Images: 27
Yup- I'd go 4.10s or 4.56s. Why spend all that money for little gain? The cost of the gears (parts) is about the same- why don't they want to do 4.10s? Probably be perfect if MPG is a concern.
I ran 4.56s on my 305/70s for awhile and it was perfectly fine. Your RPMs are per the chart- you will run about 2500-2600 RPMs at 70 but a Jeep is not a Honda and it doesn't feel like one. The torque curve is flat as a pancake and the difference in power isn't much between 2200-2800. (Just "downshift" on the highway to this RPM to get an idea). However this will lower your MPG. But screw the MPG- my Jeep is so much more fun to drive. I'm now on 35s but if I didn't want the extra clearance I actually preferred 4.56s on the smaller tire. But I like a little oomph- 4.10s would be "fine" too.
http://www.wranglerforum.com/f33/3-2...st-209000.html
JeepHerz is offline   Quote
Old 07-26-2013, 12:00 PM   #9
Jeeper
 
JKWrangler2012's Avatar
 
Join Date: Oct 2011
Location: Greensburg
Posts: 600
I ran the stock 32's for a couple weeks after the initial regear... I was at nearly 3k at 65 mph and 1, 3, and 5 gears were all but obsolete. The engine didn't seem "happy" at that rpm.. At speed. If you never plan on going over 33" I'd suggest 4.10s with the auto.
JKWrangler2012 is offline   Quote
Old 07-26-2013, 12:02 PM   #10
Jeeper
 
DJL2's Avatar
 
Join Date: Apr 2012
Location: The center of the universe, NC
Posts: 860
Just gotta go your own calculations - it's easy! Check it out:

New Tire Diameter / Current Tire Diameter = Tire Diameter Ratio (TDR)

Your TDR will determine your RPM change (decrease in the case of larger tires) versus your stock setup.

New Gear Ratio / Current Gear Ratio = Gear Swap Ratio (GSR, not gun shot residue ,p).

The GSR will determine how much your RPM (engine speed) changes for a given road speed. For 3.21 to 4.56 it's....wait for it...1.42. That means if you were going X miles per hour at 2000 RPM before, you are now doing 2840 RPM now. That's pretty significant.

Lets say you are running a true 32" tire and you switch to a true 33" tire - that makes your TDR 1.03. I think you can see where this is going. 2840 / 1.03 = 2760 RPM. In other words, you are not getting much back with such a small change in tire Diameter.

Going to a true 35" tire means 2840 RPM becomes 2600 RPM.
Going to a true 37" tire means 2840 RPM becomes 2530 RPM.

I already did some other math this morning, so hopefully my brain didn't flame out and bolo any of that.
DJL2 is offline   Quote
Old 07-26-2013, 12:07 PM   #11
Jeeper
 
JeepHerz's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 3,032
Images: 27
Quote:
Originally Posted by DJL2 View Post
Just gotta go your own calculations - it's easy! Check it out:

New Tire Diameter / Current Tire Diameter = Tire Diameter Ratio (TDR)

Your TDR will determine your RPM change (decrease in the case of larger tires) versus your stock setup.

New Gear Ratio / Current Gear Ratio = Gear Swap Ratio (GSR, not gun shot residue ,p).

The GSR will determine how much your RPM (engine speed) changes for a given road speed. For 3.21 to 4.56 it's....wait for it...1.42. That means if you were going X miles per hour at 2000 RPM before, you are now doing 2840 RPM now. That's pretty significant.

Lets say you are running a true 32" tire and you switch to a true 33" tire - that makes your TDR 1.03. I think you can see where this is going. 2840 / 1.03 = 2760 RPM. In other words, you are not getting much back with such a small change in tire Diameter.

Going to a true 35" tire means 2840 RPM becomes 2600 RPM.
Going to a true 37" tire means 2840 RPM becomes 2530 RPM.

I already did some other math this morning, so hopefully my brain didn't flame out and bolo any of that.

Or just use this. Its Friday after all. I hate to do math on a Friday. Found this to be pretty accurate.
Gear Ratio Calculator
JeepHerz is offline   Quote
Old 07-26-2013, 12:08 PM   #12
Jeeper
 
jadmt's Avatar
 
Join Date: Sep 2012
Location: missoula
Posts: 7,794
I test drove a 2013 2 dr rubicon last week it had a 6 speed and 4.10's with stock tires ~32" it was about 2500 rpm at 70mph.
jadmt is offline   Quote
Old 07-26-2013, 12:33 PM   #13
Jeeper
 
New2012JEEP's Avatar
 
Join Date: Dec 2011
Location: NB, FL
Posts: 1,418
Quote:
Originally Posted by JKWrangler2012 View Post
I ran the stock 32's for a couple weeks after the initial regear... I was at nearly 3k at 65 mph and 1, 3, and 5 gears were all but obsolete. The engine didn't seem "happy" at that rpm.. At speed. If you never plan on going over 33" I'd suggest 4.10s with the auto.
This is what I'm worried about, 2800 rpms just seems excessive for this engine. 600 extra rpms will cause premature and excessive wear IMO.

I still think 3.73 is way to go, I was just a little shocked they recommended 4.56. This is a jeep specialty shop too. I plan to stay on 33 duratracs for the life of vehicle, so not going bigger on tires.

I think 4.10 would be way to go if the Rubi people Seem to like that setup, seeing I have to pay the $1500.
__________________
2014 JKUS
OME 2" HD, MB 72 15's on 33" Goodyear DT's, Synergy Metal Grab Handles, ORO Center License Plate Bracket with LED Lights, Vector Offroad LPD, TrukLite Heads
New2012JEEP is offline   Quote
Old 07-26-2013, 12:34 PM   #14
Jeeper
 
New2012JEEP's Avatar
 
Join Date: Dec 2011
Location: NB, FL
Posts: 1,418
Quote:
Originally Posted by DJL2 View Post
Just gotta go your own calculations - it's easy! Check it out:

New Tire Diameter / Current Tire Diameter = Tire Diameter Ratio (TDR)

Your TDR will determine your RPM change (decrease in the case of larger tires) versus your stock setup.

New Gear Ratio / Current Gear Ratio = Gear Swap Ratio (GSR, not gun shot residue ,p).

The GSR will determine how much your RPM (engine speed) changes for a given road speed. For 3.21 to 4.56 it's....wait for it...1.42. That means if you were going X miles per hour at 2000 RPM before, you are now doing 2840 RPM now. That's pretty significant.

Lets say you are running a true 32" tire and you switch to a true 33" tire - that makes your TDR 1.03. I think you can see where this is going. 2840 / 1.03 = 2760 RPM. In other words, you are not getting much back with such a small change in tire Diameter.

Going to a true 35" tire means 2840 RPM becomes 2600 RPM.
Going to a true 37" tire means 2840 RPM becomes 2530 RPM.

I already did some other math this morning, so hopefully my brain didn't flame out and bolo any of that.
Dang, thanks for this!
__________________
2014 JKUS
OME 2" HD, MB 72 15's on 33" Goodyear DT's, Synergy Metal Grab Handles, ORO Center License Plate Bracket with LED Lights, Vector Offroad LPD, TrukLite Heads
New2012JEEP is offline   Quote
Old 07-26-2013, 12:49 PM   #15
Jeeper
 
jadmt's Avatar
 
Join Date: Sep 2012
Location: missoula
Posts: 7,794
Quote:
Originally Posted by New2012JEEP View Post
This is what I'm worried about, 2800 rpms just seems excessive for this engine. 600 extra rpms will cause premature and excessive wear IMO.

I still think 3.73 is way to go, I was just a little shocked they recommended 4.56. This is a jeep specialty shop too. I plan to stay on 33 duratracs for the life of vehicle, so not going bigger on tires.

I think 4.10 would be way to go if the Rubi people Seem to like that setup, seeing I have to pay the $1500.
I have found that many specialty shops are still not familiar with the 3.6L so they are basing recommendations off earlier models that had lower power and worse trannies. The new auto is also head and shoulders better then the pre 12 autos so that makes a big difference too. Test drive a 4.10 Rubi and you will get an idea of what it is like. On a modern engine using good oil I doubt the long term effect of 2500 rpms vs 2000 rpms amount to much as far as wear goes.
jadmt is offline   Quote
Old 07-26-2013, 12:55 PM   #16
Jeeper
 
DJL2's Avatar
 
Join Date: Apr 2012
Location: The center of the universe, NC
Posts: 860
Quote:
Originally Posted by jadmt View Post
I test drove a 2013 2 dr rubicon last week it had a 6 speed and 4.10's with stock tires ~32" it was about 2500 rpm at 70mph.
I can confirm - my 2012 JK Unlimited Rubicon on its stock tires runs right about 2500 RPM at 70. 2000 RPM is about 57 MPH or so.

I might actually see better fuel economy out of 35 inch tires because then I could just run 5th gear at around 2450 rpm all the way to and from work at about 62 mph. Otherwise, I am around 2200 rpm or so, and the power for hills and such just isn't there without a down shift. Using cruise control, I actually see better economy running about 57 mph and 2500 or so RPM in 5th gear than I do at the same speed, 2000 RPM in 6th gear. Every time I hit a hill, I can bury the pedal...and still struggle to maintain speed. 62 MPH is really where I want to cruise anyway, so I end up doing a lot of gear box rowing to keep the JK moving forward without wasting fuel. The Jeep makes noticeably better power at around 2500 rpm...so, a tire choice that lets me run the speed and RPM combo I want the whole way to work might just balance out the extra weight/friction. Muah.
DJL2 is offline   Quote
Old 07-26-2013, 01:33 PM   #17
yeah,,,, im that good

5-Year WF Supporting Member
 
panthermark's Avatar
 
Join Date: Aug 2011
Location: Chicago-land
Posts: 10,235
Images: 13
Quote:
Originally Posted by jadmt View Post
I have found that many specialty shops are still not familiar with the 3.6L so they are basing recommendations off earlier models that had lower power and worse trannies. The new auto is also head and shoulders better then the pre 12 autos so that makes a big difference too. Test drive a 4.10 Rubi and you will get an idea of what it is like. On a modern engine using good oil I doubt the long term effect of 2500 rpms vs 2000 rpms amount to much as far as wear goes.
Agreed...
I think there /wasis a bit of a learning curve on the 3.6 and especially the W5A580 tranny. Sometimes people focus on the axle ratio, and forget the drive ratio.
4.10's on the 3.6/W5A580 are a lot different than 4.10's on the 3.8/42RLE
__________________
2013 Sahara Unlimited
Billet - Auto - 3.73 - Connectivity - Painted Hardtop - LSD - Remote Start - Saddle Leather - Side Airbags

I may mall crawl...but I look good doing it.....
panthermark is online now   Quote
Old 07-26-2013, 01:58 PM   #18
Jeeper
 
Blkfenderslookbetter's Avatar
 
Join Date: Aug 2012
Posts: 621
Quote:
Originally Posted by jadmt View Post
I have found that many specialty shops are still not familiar with the 3.6L so they are basing recommendations off earlier models that had lower power and worse trannies. The new auto is also head and shoulders better then the pre 12 autos so that makes a big difference too. Test drive a 4.10 Rubi and you will get an idea of what it is like. On a modern engine using good oil I doubt the long term effect of 2500 rpms vs 2000 rpms amount to much as far as wear goes.
I think there are too many "specialty" shops that just get too much credit for stuff they just don't know about. They have the tools and the know how to install, but that doesn't mean they have the knowledge to know "what" to install.

4.56's on 35's is pretty aggressive, makes a nice crawler, not so nice on the highway. On 33's it just seems like a bad idea.

I have the 3.73 gears with 35's and a 6 sp tranny. Overall, I'd say that I'm very satisfied. I get 18 mpg over all, and 70 mph is 2050 rpm. If I had $$ to blow, I might be tempted to go to 4.10's but the cost would outweigh any benefit, I think. If you're re-gearing from 3.21, then I'd probably go to the 4.10, especially if you're going to run 35's. But if you're not going any larger than 33 (right! ) then the 3.73 will be good.
__________________
If I told you I was a pathological liar... would you believe me?
Blkfenderslookbetter is offline   Quote
Old 07-26-2013, 02:29 PM   #19
Jeeper
 
live_slow's Avatar
 
Join Date: Apr 2013
Posts: 666
Quote:
Originally Posted by New2012JEEP View Post
This is what I'm worried about, 2800 rpms just seems excessive for this engine. 600 extra rpms will cause premature and excessive wear IMO.

I still think 3.73 is way to go, I was just a little shocked they recommended 4.56. This is a jeep specialty shop too. I plan to stay on 33 duratracs for the life of vehicle, so not going bigger on tires.

I think 4.10 would be way to go if the Rubi people Seem to like that setup, seeing I have to pay the $1500.
That sounds good (albeit expensive), but I totally disagree with your statement about 600 extra RPMs being excessive for the engine.

This engine was made to rev. It ain't even awake yet at 2K.

In fact, the same engine is sold in a vehicle that runs on 3.21 and 4.10 from the factory. The difference at speed in those gear ratios is around 600 RPM.
__________________
IIIIII

Just another Billet Silver Metallic. It blends.
2013 | JK | 23R | 2"M | 33s on 15s |
live_slow is offline   Quote
Old 07-26-2013, 02:38 PM   #20
Jeeper
 
sgtkersh's Avatar
 
Join Date: Jan 2013
Posts: 257
I have a 2013 JKU 6 speed and went from 3.21s to 4.56s on 33" Duratracs. It was a great setup off road but a little aggressive on the highway. About 2750 RPMs at 70. Now I'm running 35" KM2s and its very nice on the highway and still a beast off road.


Sent from AutoGuide.com App
__________________
2013 JKU Sport, Sahara tires/rims - everything else in progress
sgtkersh is offline   Quote
Old 07-26-2013, 02:40 PM   #21
Jeeper
 
New2012JEEP's Avatar
 
Join Date: Dec 2011
Location: NB, FL
Posts: 1,418
Quote:
Originally Posted by live_slow View Post
That sounds good (albeit expensive), but I totally disagree with your statement about 600 extra RPMs being excessive for the engine.

This engine was made to rev. It ain't even awake yet at 2K.

In fact, the same engine is sold in a vehicle that runs on 3.21 and 4.10 from the factory. The difference at speed in those gear ratios is around 600 RPM.

This sounds good to me, and is a really good point. If I remember the MPG sticker was not too different on the 4.1 rubicon from what I bought.

I guess I just really need to test drive a jeep with 4.10 and see what it feels like driving. Maybe the engine is good to go at 2500 to 2600 RPM. 3000 seems really high though
__________________
2014 JKUS
OME 2" HD, MB 72 15's on 33" Goodyear DT's, Synergy Metal Grab Handles, ORO Center License Plate Bracket with LED Lights, Vector Offroad LPD, TrukLite Heads
New2012JEEP is offline   Quote
Old 07-26-2013, 03:18 PM   #22
Jeeper
 
live_slow's Avatar
 
Join Date: Apr 2013
Posts: 666
Quote:
Originally Posted by New2012JEEP View Post
This sounds good to me, and is a really good point. If I remember the MPG sticker was not too different on the 4.1 rubicon from what I bought.

I guess I just really need to test drive a jeep with 4.10 and see what it feels like driving. Maybe the engine is good to go at 2500 to 2600 RPM. 3000 seems really high though
Yeah, dont' get me wrong.

Look, I buzzed up and down the east coast in my 4.0L XJ with 4.56 and 32" tires. I'd sit all day at 2.5 to 3K keeping up with traffic on I 95. (Went from MD to GA and back like six times in it)

It sucked gas, but it wasn't a serious problem.

It's all about the expense when you're talking about having gears done. Since it ain't cheap, it's a heck of a decision.

Is 4.56 too low for 33" tires that ain't going to be 33 inches on the ground?

Yes. It is too low unless you are going for performance over everything and nothing else.

I guess my point was it isn't too low because of the extra RPMs.

You're right there on the "return on investment" problem.

3.21 to 4.10 in your situation would be like night and day
4.10 to 4.56 in your situation wouldn't be noticeable

Since you're spending the money anyway and many modern Jeepers are going right to 35s, folks will suggest 4.56 while you're in there. (Also lockers, lift, maybe 37s, etc. That's how it goes!)
__________________
IIIIII

Just another Billet Silver Metallic. It blends.
2013 | JK | 23R | 2"M | 33s on 15s |
live_slow is offline   Quote
Old 07-26-2013, 04:39 PM   #23
Jeeper
 
sgtkersh's Avatar
 
Join Date: Jan 2013
Posts: 257
Quote:
Originally Posted by live_slow View Post
Yeah, dont' get me wrong.

Look, I buzzed up and down the east coast in my 4.0L XJ with 4.56 and 32" tires. I'd sit all day at 2.5 to 3K keeping up with traffic on I 95. (Went from MD to GA and back like six times in it)

It sucked gas, but it wasn't a serious problem.

It's all about the expense when you're talking about having gears done. Since it ain't cheap, it's a heck of a decision.

Is 4.56 too low for 33" tires that ain't going to be 33 inches on the ground?

Yes. It is too low unless you are going for performance over everything and nothing else.

I guess my point was it isn't too low because of the extra RPMs.

You're right there on the "return on investment" problem.

3.21 to 4.10 in your situation would be like night and day
4.10 to 4.56 in your situation wouldn't be noticeable

Since you're spending the money anyway and many modern Jeepers are going right to 35s, folks will suggest 4.56 while you're in there. (Also lockers, lift, maybe 37s, etc. That's how it goes!)
This is good advice.


Sent from AutoGuide.com App
__________________
2013 JKU Sport, Sahara tires/rims - everything else in progress
sgtkersh is offline   Quote
Old 07-26-2013, 05:00 PM   #24
yeah,,,, im that good

5-Year WF Supporting Member
 
panthermark's Avatar
 
Join Date: Aug 2011
Location: Chicago-land
Posts: 10,235
Images: 13
That is the thing with regearing....and Wrangler's in general....you almost need to know in advance what you are going to do to prevent the double spending of money down the line.


Being that you have a 2012, the cost of upgrading 3.21's to 3.73's ranged between $0, $50, and $95. The upgrade then could have saved you $1400-$1500 now...bummer. Live and learn...
__________________
2013 Sahara Unlimited
Billet - Auto - 3.73 - Connectivity - Painted Hardtop - LSD - Remote Start - Saddle Leather - Side Airbags

I may mall crawl...but I look good doing it.....
panthermark is online now   Quote
Old 07-26-2013, 05:52 PM   #25
Jeeper
 
JeepHerz's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 3,032
Images: 27
Quote:
Originally Posted by panthermark View Post
That is the thing with regearing....and Wrangler's in general....you almost need to know in advance what you are going to do to prevent the double spending of money down the line.


Being that you have a 2012, the cost of upgrading 3.21's to 3.73's ranged between $0, $50, and $95. The upgrade then could have saved you $1400-$1500 now...bummer. Live and learn...
Don't remind me. I begin to see red spots behind me eyes and a weird boiling sensation in my ears.
Seems obvious now- but in retrospect someone had to throw 35s with 3.21s on a Pentastar to know what it would do- or not do. Plenty of folks thought the new engine, 5 speed tranny and whiz-bang technology (LOL) would provide advantages prior models did not. In some ways it did- in others ways it sent many of us to the bank. And the forum gear thread asylum.
I can specifically remember being determined NOT to get 3.73s- I wanted a stripped down basic JK I could tinker with."Its a Jeep- not a sports car. And I am NOT towing with it". Stomp, stomp..
There goes that boiling noise again.......
JeepHerz is offline   Quote
Old 07-26-2013, 06:17 PM   #26
Jeeper
 
Muddr1's Avatar
 
Join Date: Nov 2009
Location: New Hampshire
Posts: 459
I have 33's and maybe in the spring, I am going to put in 4.10. I have the 12 with the auto, I think its going to give me the best performance with the 33's and there is still room there if I decide to go 35's.
__________________
Keep calm, Chive On
Muddr1 is offline   Quote
Old 07-26-2013, 06:25 PM   #27
Jeeper
 
DJL2's Avatar
 
Join Date: Apr 2012
Location: The center of the universe, NC
Posts: 860
FWIW, I've made the trip to and from VA and few other places with a speed limit of 70+ turning 2500-3000 RPM for extended period of time. Put around 20,000 miles on the first year...so, time will tell on that.

I've got another vehicle, I-6 w/ turbocharger, it's around 85,000 miles right now and it's normal engine speed is around 3000 rpm for most any sort of driving, though you can shift it will below the power band if you like.

Nowadays, a decent engine is likely to have been endurance tested at high RPM and high speed for hundreds, if not thousands, of hours before it goes into a vehicle. If you get a good engine under the hood, the issue isn't usually the RPM or the operating hours - typically it's the maintenance and operational conditions that really come into play.

Also, on that note, am I the only guy that wants to see operating hours at least as much as, if not more than, the number on the odometer?

DJL2 is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Download our Mobile App

» Featured Product

All times are GMT -5. The time now is 06:41 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC