3.21 vs 3.92

[Jared B]

May I suggest when you do the video, be sure to accentuate the Differences with the engine noise & the 'NC sound-system' while driving - Windows Up & all Windows Down ! A TRUE test experience for ALL of us at Once ! ps, be sure the batteries are all charged, no glitches present and Sound turned Up on your Camera or device used !

I'm trying to put something together from the footage that I have left, unfortunately I don't know if that is going to happen, I might just have to completely do the video review over unfortunately. I did just post the written review though.

 

[AZOutdoors]

For what it's worth, I test drove two 5.7 Limiteds with the 3.21 and 3.92. I actually drove each truck twice to help make up my mind on what ratio to get. They had almost the exact truck I wanted at the dealer except it had the 3.21 gears (the 3.92 truck did not have the options I wanted). I REALLY wanted to like the 3.21 better so I wouldn't have to order one and wait. After driving them both, I decided to order one with the 3.92. My current 2012 Ram 1500 has the 3.55. I pull a boat that weighs less than 6K pounds so towing with either ratio would be fine. It just felt like the 3.92 had more pull during normal cruising. They both take off like crazy with that 8-speed but when you are cruising along at 45 or 50 and you give it a little gas, the 3.21 seemed flat until you push the gas hard enough for a down-shift. The 3.92 felt "torquier" without having to rely on a down-shift.

 

[DSOOBY]

For what it's worth, I test drove two 5.7 Limiteds with the 3.21 and 3.92. I actually drove each truck twice to help make up my mind on what ratio to get. They had almost the exact truck I wanted at the dealer except it had the 3.21 gears (the 3.92 truck did not have the options I wanted). I REALLY wanted to like the 3.21 better so I wouldn't have to order one and wait. After driving them both, I decided to order one with the 3.92. My current 2012 Ram 1500 has the 3.55. I pull a boat that weighs less than 6K pounds so towing with either ratio would be fine. It just felt like the 3.92 had more pull during normal cruising. They both take off like crazy with that 8-speed but when you are cruising along at 45 or 50 and you give it a little gas, the 3.21 seemed flat until you push the gas hard enough for a down-shift. The 3.92 felt "torquier" without having to rely on a down-shift.

That's a great way to put it. That has been my experience with test driving 3.21 geared trucks, and driving my own withthe 3.92.

 

[Ramajama]

The real-world economy difference between a 3.92 and 3.21 is almost inconceivable. Buy a 3.92.

Exactly! I just told my buddy to make sure he gets a 3.92 equipped RAM. They are the way to go if you want more miles of smiles. You just don’t sacrifice any MPGs unless the stars are aligned and specific conditions are met, then the 3.21 will net a tiny bit better MPG. But if you’re one of those guys that doesn’t understand gearing or just don’t give a crap, go ahead and buy a 3.21 equipped truck.

 

[devildodge]

People with the 3.92 are probably doing more spirited acceleration, cause it's fun.

It is like when you get a louder exhaust, and you start revving it and staying in the throttle to hear it sing.

Mpg goes down.

I drive a 488 cu in V10. I don't concern myself with miles per gallon...just were the gas stations are on the trip

 

[Ramajama]

Ive had three RAM trucks with 3.92 rear end and always got 17-19. I don’t know what’s up with the guys reporting 13-14?

 

[techieanalyst]

I test drove a 3.21, felt sluggish (thats my opinion, floored it and it went but it wasn't exciting), I have 3.92 on my ram and had it on my ford, the ram hitting the gas it will squeal the tires some, even the ford was fun and peppy but i couldnt imagine not having the 3.92 on the ram and hemi

 

[troutspinner]

@techieanalyst said it perfectly, I have noticed a similar experience between 3.21 and 3.92.

FWIW, I owned a 2011 F150 with a 3.5 Ecoboost and 3.55 gears. When I moved to my 2014 Ram with 5.7 and 3.92s, on average I saw a 1 mpg increase making the Ram better on gas. The 2.7 is going to work harder and just like the fuel numbers on my F150’s sticker, don’t expect to achieve them.

 

[Jus Cruisin]

I test drove a 3.21, felt sluggish (thats my opinion, floored it and it went but it wasn't exciting), I have 3.92 on my ram and had it on my ford, the ram hitting the gas it will squeal the tires some, even the ford was fun and peppy but i couldnt imagine not having the 3.92 on the ram and hemi

I have a different outlook on my trucks. I don't care what gears they have, they'll feel like a slug. Mine keeps up with traffic and will accomplish what I want it to do. I always have a couple cars that'll hit 60 in about 3 seconds. I've only owned one truck that I considered to be relatively quick - a 1999 Ford Lightning. Twenty years later, it would just be so so by today's standards yet it would still show any 2019 Ram its taillights.

 

[techieanalyst]

I have a different outlook on my trucks. I don't care what gears they have, they'll feel like a slug. Mine keeps up with traffic and will accomplish what I want it to do. I always have a couple cars that'll hit 60 in about 3 seconds. I've only owned one truck that I considered to be relatively quick - a 1999 Ford Lightning. Twenty years later, it would just be so so by today's standards yet it would still show any 2019 Ram its taillights.

I said my opinion when comparing 3.92 in the 5.7 and 5.0 ford, this wasnt to say its slow

 

[Brandon_Vickers]

I am looking to get a 2019 1500 Limited 4x4 with the 5.7 and E-Torque. I will be doing mostly city driving, Maybe one trip or so per month where I go on the highway (~65-70 MPH) for 150 miles round trip and a couple trips a year where I am on the Interstate (~70-80 MPH) for ~600 miles round trip. I never plan to tow much, if at all, of any significance. I am a bit of a lead foot change lanes often.

I was planning to get the 3.21 because that seemed to be correct for someone who is not going to be towing anything and would save a little gas to boot. But after reading this thread, it almost sounds I would be better of getting the 3.92. Not just for the little extra fun pep, but it sounds like I wouldn't see any fuel savings with the 3.21 and might even see more savings with the 3.92.

Does this seem right? I have not been able to find any real word charts or data which compares the two gear ratios.

 

[troutspinner]

I am looking to get a 2019 1500 Limited with the 5.7 and E-Torque. I will be doing mostly city driving, Maybe one trip or so per month where I go on the highway (~65-70 MPH) for 150 miles round trip and a couple trips a year where I am on the Interstate (~70-80 MPH) for ~600 miles round trip. I never plan to tow much, if at all, of any significance. I am a bit of a lead foot change lanes often.

I was planning to get the 3.21 because that seemed to be correct for someone who is not going to be towing anything and would save a little gas to boot. But after reading this thread, it almost sounds I would be better of getting the 3.92. Not just for the little extra fun pep, but it sounds like I wouldn't see any fuel savings with the 3.21 and might even see more savings with the 3.92.

Does this seem right? I have not been able to find any real word charts or data which compares the two gear ratios.

Is this going to be your first truck? If not, what does your previous truck have? If so, what did your car have in gear choices and how did you like your choice?

If I had to offer an opinion, based off of your stated needs, I’d say 3.21 but if you plan to go to larger wheels, you may want to adjust accordingly.

 

[RenoRam]

I am looking to get a 2019 1500 Limited with the 5.7 and E-Torque. I will be doing mostly city driving, Maybe one trip or so per month where I go on the highway (~65-70 MPH) for 150 miles round trip and a couple trips a year where I am on the Interstate (~70-80 MPH) for ~600 miles round trip. I never plan to tow much, if at all, of any significance. I am a bit of a lead foot change lanes often.

I was planning to get the 3.21 because that seemed to be correct for someone who is not going to be towing anything and would save a little gas to boot. But after reading this thread, it almost sounds I would be better of getting the 3.92. Not just for the little extra fun pep, but it sounds like I wouldn't see any fuel savings with the 3.21 and might even see more savings with the 3.92.

Does this seem right? I have not been able to find any real word charts or data which compares the two gear ratios.

IMO, the 3.92 is worth ticking the box for $95. There doesn't seem to be much mileage savings (if that is a consideration) and based on your driving style, it seems better suited for you. Additionally, should you need to tow, it is helpful.

 

[Zeronet]

I am looking to get a 2019 1500 Limited with the 5.7 and E-Torque. I will be doing mostly city driving, Maybe one trip or so per month where I go on the highway (~65-70 MPH) for 150 miles round trip and a couple trips a year where I am on the Interstate (~70-80 MPH) for ~600 miles round trip. I never plan to tow much, if at all, of any significance. I am a bit of a lead foot change lanes often.

I was planning to get the 3.21 because that seemed to be correct for someone who is not going to be towing anything and would save a little gas to boot. But after reading this thread, it almost sounds I would be better of getting the 3.92. Not just for the little extra fun pep, but it sounds like I wouldn't see any fuel savings with the 3.21 and might even see more savings with the 3.92.

Does this seem right? I have not been able to find any real word charts or data which compares the two gear ratios.

Don’t worry about mileage, these are big/heavy vehicles. The mileage will not be good.

Real world, it looks like eTorque is good for a little less than +1mpg (Fuelly.com)

The 3.92 will likely get 1mpg less around town than the 3.21. Getting better mileage with a 3.92 is highly unlikely. Since you don’t tow and don’t do a lot of highway it may be worth it for the fun factor.

The 3.92 will get 2-3mpg less at interstate highway speeds.

 

[Gman]

I was looking to go 3.92, but based on what I wanted, couldn't find it in a 3.92. I'm not one looking to drive a lifted bro-dozer. I will rarely tow (if ever), so I went with the 3.21. I haven't missed the 3.92 and am very happy with the 3.21.

...and I'm also not complaining about my mileage.

 

[Creep0321]

I was looking to go 3.92, but based on what I wanted, couldn't find it in a 3.92. I'm not one looking to drive a lifted bro-dozer. I will rarely tow (if ever), so I went with the 3.21. I haven't missed the 3.92 and am very happy with the 3.21.

...and I'm also not complaining about my mileage.

How’s your mileage?

 

[Gman]

Last time I checked, 17.7 during my evening commute home.

 

[Smashy71]

I’m averaging over 15mpg 3400 miles.

 

[filup01]

I disagree with most of the people here. I have 3.21 and average 17-17.7 MPG per tank. I drive normal, not slow but not like I’m 17 y/o either. I also live in Atlanta where traffic is hell and small portions of my commute is bumper to bumper but mostly it’s wide open interstate. I’ll settle for saying my 30 mile each way to work is a mix of city and highway.
Nonetheless, when I set the cruise at 75-80 driving to work on the interstate drinking my coffee and listening to a morning show on the radio, I see the transmission go back and forth between 7th and 8th gear on the small hills down here. Mind you, the Hemi has more than enough power to easily make it up a hill on a paved interstate at low elevation. My thoughts are that the 3.21 gears are so tall that at that speed with high wind drag and a gentle slope, the 3.92 gears wouldn’t downshift and thus, may possibly get better gas mileage than the 3.21.
This is just my theory anyway. I haven’t lifted and have stock tires on my 4X4 (Offroad package) and am 100% happy with my truck. I have another truck in my driveway right now; a 2001 Dodge 2500 4X4 Cummins. It gets marginally better fuel economy but with diesel being $1.00 at the pump per gallon and more expensive oil and fuel filter changes, I’ll drive the new gasoline truck with 3.21 gears and just drink my coffee in peace and quite while the truck downshifts. Plus, the old truck, although almost mint condition with exception to having 200k miles, is very stiff. A piece of gravel will bounce you so high that when you land, you’ll snap your spine. The new Ram is so very comfortable no matter the gears. It is a truck and not a Prius. I think it matters what you like regardless of gears. For anyone buying a new truck, today I don’t think you could do better than a Ram and I’ve recently owned all makes.

 

[Zeronet]

I disagree with most of the people here. I have 3.21 and average 17-17.7 MPG per tank. I drive normal, not slow but not like I’m 17 y/o either. I also live in Atlanta where traffic is hell and small portions of my commute is bumper to bumper but mostly it’s wide open interstate. I’ll settle for saying my 30 mile each way to work is a mix of city and highway.
Nonetheless, when I set the cruise at 75-80 driving to work on the interstate drinking my coffee and listening to a morning show on the radio, I see the transmission go back and forth between 7th and 8th gear on the small hills down here. Mind you, the Hemi has more than enough power to easily make it up a hill on a paved interstate at low elevation. My thoughts are that the 3.21 gears are so tall that at that speed with high wind drag and a gentle slope, the 3.92 gears wouldn’t downshift and thus, may possibly get better gas mileage than the 3.21.
This is just my theory anyway. I haven’t lifted and have stock tires on my 4X4 (Offroad package) and am 100% happy with my truck. I have another truck in my driveway right now; a 2001 Dodge 2500 4X4 Cummins. It gets marginally better fuel economy but with diesel being $1.00 at the pump per gallon and more expensive oil and fuel filter changes, I’ll drive the new gasoline truck with 3.21 gears and just drink my coffee in peace and quite while the truck downshifts. Plus, the old truck, although almost mint condition with exception to having 200k miles, is very stiff. A piece of gravel will bounce you so high that when you land, you’ll snap your spine. The new Ram is so very comfortable no matter the gears. It is a truck and not a Prius. I think it matters what you like regardless of gears. For anyone buying a new truck, today I don’t think you could do better than a Ram and I’ve recently owned all makes.

Regarding the downshifting, you can easily test your theory about the 3.92 getting better mileage by doing the following;

Use your gear limit selector and set it to 8th gear to lock out MDS. Reset your mpg. Drive your normal commute and note the mpg when you arrive at your destination. This will be your 3.21 mpg for comparison.

On your next commute use your gear limit selector and set it to 7th gear. Reset your mpg. Drive your normal commute and note the mpg when you arrive at your destination. This will be your 3.92 mpg for comparison.

These numbers are just for comparison and would probably not be the actual mpg that would be obtained by either the 3.21 or 3.92 due to MDS being off in both cases.

8th gear in a 3.92 truck is almost exactly the same ratio as 7th gear in a 3.21 truck. So by doing this test you will basically be isolating the mpg difference between the two ratios.

Some may say that the results are not fair since MDS would be on more in a 3.92 truck but at 75-80mph MDS is not a factor. Around town MDS difference should be negligible since the loads on the engine would be similar; the 3.92 would run in a higher gear and the 3.21 in a lower gear to maintain the same speed.

I’d honestly be interested to see what the difference would be.