3.21 vs. 3.92

[ballgame168]

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?

 

[SpeedyV]

Please search the forums...you’ll find many posts (even in the past 24 hours) about this.

 

[devildodge]

Yes our search button works real well. You would probably have to do it for rear gear though as it has to be more than 3 characters

 

[ballgame168]

Yes our search button works real well. You would probably have to do it for rear gear though as it has to be more than 3 characters

Perhaps that’s been my problem. I keep searching and it returns no results.

 

[devildodge]

Perhaps that’s been my problem. I keep searching and it returns no results.

Search gear in titles only also. This question gets asked daily. It really is personal preference and driving style.

Gas mileage depends a lot more on you than the truck

As I said in another thread. The only difference between 3.21 and 3.92 is GCWR

3.21 is 13900
3.92 is 17000

So 3100lbs towing is the real difference. The rest is really subjective

 

[devildodge]

Ratio works well for the search also.

 

[dutchman187]

Yes our search button works real well. You would probably have to do it for rear gear though as it has to be more than 3 characters

Sometimes the forums (not just this one, but most) don't have the greatest search capabilities in my experience. A tip for anyone out there who has similar issues: if you do the forum search and can't find anything on point, go to Google and search your keywords or sentence again and then also add "5thgenrams" to it. It often brings up search results when my initial search using the forum engine did not.

 

[VenomBee]

My Rebel has the 3.92 gears and I have 275 miles on my truck. I got 18 mpg’s so far. Most of it is highway and I was running 75 mph with slight hills. I don’t have etorque. I have not seen the eco light come on yet. I wonder if that’s because there is a certain mileage for break in till it’s activated.

 

[superbird77]

My Rebel has the 3.92 gears and I have 275 miles on my truck. I got 18 mpg’s so far. Most of it is highway and I was running 75 mph with slight hills. I don’t have etorque. I have not seen the eco light come on yet. I wonder if that’s because there is a certain mileage for break in till it’s activated.

FYI I had to go into my setup to get the ECO light to display on my driver info screen. 3:92 gears here too, seeing around 19 MPG with 800 miles on the vehicle.

 

[warvet]

you'll also run across this topic in most of the 'mpg' threads..........or 'gas mileage' threads without even really doing a search.

 

[ballgame168]

Just drove a 3.21 and 3.92 back to back at a local dealership. 3.92 definitely felt heavier and a quicker first step. But honestly, the difference from the 3.21 didn’t seem like much (felt lighter but still peppy). For the potential MPG hit, I just can’t really see doing the 3.92, especially because I am not really doing much towing. Think it may be the 3.21 for me and accept a slower first step but better mileage.

 

[356]

Just drove a 3.21 and 3.92 back to back at a local dealership. 3.92 definitely felt heavier and a quicker first step. But honestly, the difference from the 3.21 didn’t seem like much (felt lighter but still peppy). For the potential MPG hit, I just can’t really see doing the 3.92, especially because I am not really doing much towing. Think it may be the 3.21 for me and accept a slower first step but better mileage.

I too drove both before placing my order. I really didn't notice much difference either, although I am sure that when towing, the difference is noticeable. In another post I noted I just returned 21.4 mpg on my last tank with a moderate load.

 

[YoAdrian]

I got 3.92 gears for towing capacity and happy acceleration and offset the mpg hit by adding eTorque. Made sense to me (even if the math doesn’t add up perfectly).

 

[superbird77]

My attempt to simplify this topic.... If you tow regularly, specifically something with decent weight get the 3:92. If you never tow anything or only a few times a year get the 3:21. Guys who tow regularly seem to know MPG's are what they are. I'd rather have the 3:92 for my boat towing needs. By nature any V8 crew cab truck is probably gonna eat some fuel regardless of 3:21 or 3:92.

 

[ballgame168]

My attempt to simplify this topic.... If you tow regularly, specifically something with decent weight get the 3:92. If you never tow anything or only a few times a year get the 3:21. Guys who tow regularly seem to know MPG's are what they are. I'd rather have the 3:92 for my boat towing needs. By nature any V8 crew cab truck is probably gonna eat some fuel regardless of 3:21 or 3:92.

Makes sense to me. Just needed to see for myself.

 

[wolf1776]

My attempt to simplify this topic.... If you tow regularly, specifically something with decent weight get the 3:92. If you never tow anything or only a few times a year get the 3:21. Guys who tow regularly seem to know MPG's are what they are. I'd rather have the 3:92 for my boat towing needs. By nature any V8 crew cab truck is probably gonna eat some fuel regardless of 3:21 or 3:92.

What if your truck is lifted 2-4 inches? I dont plan on doing any towing but was advised to go w/ the 3.92 if you lift and are running larger/heavier tires. Do you think that's true?

 

[wolf1776]

My attempt to simplify this topic.... If you tow regularly, specifically something with decent weight get the 3:92. If you never tow anything or only a few times a year get the 3:21. Guys who tow regularly seem to know MPG's are what they are. I'd rather have the 3:92 for my boat towing needs. By nature any V8 crew cab truck is probably gonna eat some fuel regardless of 3:21 or 3:92.

What kind of real world mpg are you getting with the eTorque?

 

[superbird77]

What kind of real world mpg are you getting with the eTorque?

I don't have the eTorque FYI. Just the normal 5.7. I have also read that the 3:92 gears would be better for larger tires. This certainly makes sense but I don't have real world data to back that claim up.

 

[Ramjack]

I don't have the eTorque FYI. Just the normal 5.7. I have also read that the 3:92 gears would be better for larger tires. This certainly makes sense but I don't have real world data to back that claim up.

Yes, because taller tires reduce the effective torque and horsepower delivered to the ground.. Having a 3.92 rear vs 3.21 puts you in a better starting place, by about 20%.

 

[VenomBee]

FYI I had to go into my setup to get the ECO light to display on my driver info screen. 3:92 gears here too, seeing around 19 MPG with 800 miles on the vehicle.

I got the eco light to come on. Thanks for the info. It’s doesn't come on often. Hopefully when the break in is over it will loosen up the motor and the mpg’s will go up. Averaging about 17 right now. Noticing about 18 or 19 on the highway today.