3.21 vs. 3.92

[ballgame168]

So I made up my mind to go 3.21 after driving both. Then found out that the off road package (which I have wanted mainly for 1” lift on air ride) requires 3.92 b/c of elocker. Now admittedly, I am not going to do serious off-reading, at worst mud and fields while hunting and deep snow and ice during bad storms.

My other option would be to add the protection package (skid plates), add anti slip diff, 20” wheels, and keep 3.21 for same cost as off road package. I would not get 1” lift, upgraded shocks, elocker, full size spare, hill descent control or off road tires. Though I think I would get potentially much better gas mileage.

Anybody have any thoughts?

 

[356]

So I made up my mind to go 3.21 after driving both. Then found out that the off road package (which I have wanted mainly for 1” lift on air ride) requires 3.92 b/c of elocker. Now admittedly, I am not going to do serious off-reading, at worst mud and fields while hunting and deep snow and ice during bad storms.

My other option would be to add the protection package (skid plates), add anti slip diff, 20” wheels, and keep 3.21 for same cost as off road package. I would not get 1” lift, upgraded shocks, elocker, full size spare, hill descent control or off road tires. Though I think I would get potentially much better gas mileage.

Anybody have any thoughts?

You automatically have brake limited slip with the traction control. For off road I'd recommend 18" wheels. If mpg is a goal, remember that lifts and some options that add lots of weight will impact mileage.

 

[alow]

I have 3.21 and the off road pkg. Are you ordering or looking on lots? If I remember correctly from my time of order the gear ratio is just a clicky box to change. There was no hangup at the time of selection. If you are checking on the website\online config it might not let you do it.

 

[ballgame168]

I have 3.21 and the off road pkg. Are you ordering or looking on lots? If I remember correctly from my time of order the gear ratio is just a clicky box to change. There was no hangup at the time of selection. If you are checking on the website\online config it might not let you do it.

Wow - very interesting! I built the order on the website and gave specs to the dealer. I didn't see the ability to change it online (even though I selected 3.21 I thought it changed to 3.92 when ORG was selected). I will have to tell them to change to the 3.21. I see you also have the non-etorque. How is your MPG with the regular Hemi, ORG and 3.21?

 

[devildodge]

This question has come up before, like all the 3.21 3.92 talk.

https://5thgenrams.com/complete-201...black-packages-multifunction-tailgate-listed/

 

[VenomBee]

I have about 550 miles on my Rebel and I’m averaging about 18.5 mpg on mostly highway. I’m pretty happy. Motor is not even broken in yet. I don’t have E-torque either. I didn’t want E-torque because I was worried about the cost changing the battery pack later.

 

[alacombe]

I have the ORG w/ 3.92 v8 hemi with no e- torqure currently getting 13.2 mpg

 

[Gondul]

I have the ORG w/ 3.92 v8 hemi with no e- torqure currently getting 13.2 mpg

It that city, combined, or highway? thanks...

 

[alacombe]

It that city, combined, or highway? thanks...

all city. I dont do really any highway driving

 

[Lawdog]

Stock 18" tires on my new Larami vs going to a 35x 12.50 R 20 a gear ratios calculator that showed 3.92 becomes an effective ratio of 3.59

 

[Michael_D]

So I made up my mind to go 3.21 after driving both. Then found out that the off road package (which I have wanted mainly for 1” lift on air ride) requires 3.92 b/c of elocker. Now admittedly, I am not going to do serious off-reading, at worst mud and fields while hunting and deep snow and ice during bad storms.

My other option would be to add the protection package (skid plates), add anti slip diff, 20” wheels, and keep 3.21 for same cost as off road package. I would not get 1” lift, upgraded shocks, elocker, full size spare, hill descent control or off road tires. Though I think I would get potentially much better gas mileage.

Anybody have any thoughts?

I ordered mine. 3.21, e-lock diff, off road package, 6` 4" bed. It showed up that way.

 

[alacombe]

So I made up my mind to go 3.21 after driving both. Then found out that the off road package (which I have wanted mainly for 1” lift on air ride) requires 3.92 b/c of elocker. Now admittedly, I am not going to do serious off-reading, at worst mud and fields while hunting and deep snow and ice during bad storms.

My other option would be to add the protection package (skid plates), add anti slip diff, 20” wheels, and keep 3.21 for same cost as off road package. I would not get 1” lift, upgraded shocks, elocker, full size spare, hill descent control or off road tires. Though I think I would get potentially much better gas mileage.

Anybody have any thoughts?

I have the off road package with eh 3.92 etc. Honestly, its a waste. I dont see myself ever using the e-locker. Skid plates are cool but dont really need them. The skid plates, lift, and 3.92 gears, 2oin rims etc just ruin gas milage but w.e I have it not anyways. The faulken tires are nothing special they dont look that much different.

 

[Bwarren2]

I am right at the finish line to order a non-eTorque Limited with off road group and 3.92. Seems like I have chosen the trifecta of bad gas mileage. Originally planned on getting the eTorque but not sure cost difference is worth it, new tech/engine relative to the traditional and the fact that production is on hold til January. While I don’t plan on doing hard core off reading, I like the idea of the 1” loft which it sounds like is the only way to get a lift on the air ride. I guess I could consider the elocker (which I want), the protection group and wheel upgrade to 20” (which I also want). Wouldn’t be the true ORG but may get me close. My preference is to keep regular Hemi and ORG.

So the last question is 3.21 vs. 3.92. What kind of real world MPG difference do these have? Seems like everyone that has 3.92 loves it but that it has a significant impact on mileage. I don’t do much towing and I will not be trying to race my truck. I am also coming from a 2007 Honda Ridgeline with a V6 so it’s not like I am driving a performance related vehicle. So what are people’s thoughts on whether I would be ok with the 3.21 and what MPG benefit do you think I could expect with it while having the regular Hemi and off road group?

3.21 without e torque will be very slow off the line.

 

[Ramjack]

3.21 without e torque will be very slow off the line.

I don't think the etorque will make a difference since it is good for no more than the first 1/2 revolution of the wheel off the line.

 

[John813]

FWIW:

I've been driving on the highway locking out 8th gear @ 80mph just to see the difference in mileage at ~1,700 rpm in 8th and ~2,100rpm in 7th.
Cruise control and flat roads, same conditions for both "runs".
At worst, the computer estimated 1mpg lost in some stretches, and others, it was the exact same 20-21 mpg.

Anyways, I may end up switching to a 3.92, and yes, I should of thought about it more before buying the truck, cause it'll cost more now. (2wd though).

The gears are unchanged between the 4th gen(2011+) and the 5th gen, right?

 

[Zeronet]

FWIW:

I've been driving on the highway locking out 8th gear @ 80mph just to see the difference in mileage at ~1,700 rpm in 8th and ~2,100rpm in 7th.
Cruise control and flat roads, same conditions for both "runs".
At worst, the computer estimated 1mpg lost in some stretches, and others, it was the exact same 20-21 mpg.

Anyways, I may end up switching to a 3.92, and yes, I should of thought about it more before buying the truck, cause it'll cost more now. (2wd though).

The gears are unchanged between the 4th gen(2011+) and the 5th gen, right?

Thanks for doing this test. I’ve been wondering what the mpg difference would be. One question, when running WITHOUT the 8th gear locked out, did you change the gear selector to 8th or did you just run in Drive?

Reason for asking is that when you Use the gear selector it disables MDS. So to do an apples to apples comparison you would need to use the gear selector for both runs. Although at 80mph MDS may not be a factor.

3.92 may not be affecting highway mpg as much as I thought

 

[Zeronet]

Questions for 3.21 gear vs 3.92 related to down shifting at rural or interstate highways speeds. I’d really appreciate your experience and thoughts on this.

-What gear do you have?

-Does your truck like to downshift for slight or moderate acceleration while cruising?

-Does your truck downshift occasionally when climbing a highway overpass?

-Do you ever find yourself locking out 8th gear to keep the truck from shifting a lot in areas with small hills?

 

[John813]

Thanks for doing this test. I’ve been wondering what the mpg difference would be. One question, when running WITHOUT the 8th gear locked out, did you change the gear selector to 8th or did you just run in Drive?

Reason for asking is that when you Use the gear selector it disables MDS. So to do an apples to apples comparison you would need to use the gear selector for both runs. Although at 80mph MDS may not be a factor.

3.92 may not be affecting highway mpg as much as I thought

Ran it in 8th, so MDS was disabled.

I think the RPM for both 8th gear and 7th gear were higher than what I posted, ~1800/1,900rpm in 8th and maybe ~2,200 rpm for 7th gear.

Questions for 3.21 gear vs 3.92 related to down shifting at rural or interstate highways speeds. I’d really appreciate your experience and thoughts on this.

-What gear do you have?

-Does your truck like to downshift for slight or moderate acceleration while cruising?

-Does your truck downshift occasionally when climbing a highway overpass?

-Do you ever find yourself locking out 8th gear to keep the truck from shifting a lot in areas with small hills?

1.3.21
2 & 3. Yes. Even in Florida with flat roads the truck loves to downshift from 8th a lot. For example, cruise control @ 80, see a slow down to 75 and then get open road and reactivate CC. The truck will down shift there. It'll downshift at the same speed over bridges as well. Anything under 2k RPM in my experience it'll want to downshift.
4. Not yet as S. Florida isn't too hilly.

 

[Zeronet]

Ran it in 8th, so MDS was disabled.

I think the RPM for both 8th gear and 7th gear were higher than what I posted, ~1800/1,900rpm in 8th and maybe ~2,200 rpm for 7th gear.




1.3.21
2 & 3. Yes. Even in Florida with flat roads the truck loves to downshift from 8th a lot. For example, cruise control @ 80, see a slow down to 75 and then get open road and reactivate CC. The truck will down shift there. It'll downshift at the same speed over bridges as well. Anything under 2k RPM in my experience it'll want to downshift.
4. Not yet as S. Florida isn't too hilly.

Thanks for the reply, great info. Where you at in SoFla? I’m in Davie.

 

[John813]

Thanks for the reply, great info. Where you at in SoFla? I’m in Davie.

Port St. Lucie area.