3.21 vs 3.92 Gear Ratio...will not be towing much.

[corneileous]

You're not missing anything, only the ability to tow > 8000 pounds, which you can't do anyways in a loaded Laramie due to not having enough payload.

A weight distribution hitch will help a lot with that but besides that, not everybody who tows is always going to have a loaded truck bed or loaded cab.

The 3.21 was made for guys like you and I. Just get it, you will have 0 regrets. My truck accelerates like a jack rabbit (compared to all my previous rides) so I have no idea what the 3.92 guys are talking about.

Well, I can’t say 100% but I don’t think the 2017 Laramie Longhorn 1500 with air ride that I test drove before I bought my new truck had the 3.21, or not but it sure didn’t feel as peppy to me as the one I got but I guess that’s just me. But see, even though I’m not questioning the validity of your statement but one thing you gotta keep in mind is that everybody’s idea or opinion of a smooth ride or how quick their truck accelerates is a very subjective topic.

As for the tow package, don’t get it. Just get the receiver hitch and the brake controller. If you get the tow package you would get those 2 items and also get different mirrors which are worse than the default mirrors (less features in some way, I forget how).

The only thing you lack with the tow mirrors is the ability to power fold them.


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[JoeCo]

The only thing you lack with the tow mirrors is the ability to power fold them.


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This was finally fixed for the 2021 models, now tow mirrors do power fold on the 1500's (at least for the 5th gens, not sure they updated that on the classics). The other thing you could lose (prior to 2021 MY) is the surround view camera, if the truck would have been optioned with it. However, as mentioned, if you get a 2021 you don't have to worry about losing either of those features.

 

[runamuck]

I had 3.42 rear end in my last 1500 truck and in my experience the biggest difference comes when first starting to move from a dead stop and then if you need to move out quickly when cruising on the highway say the quick jump from 60-70 or so. the 3.92 is much quicker than my last truck with 3.42..and with 3.21 I think the difference would be even greater..for all other times..probably no big deal. like others have said, both will do fine, just a personal preference.

 

[corneileous]

This was finally fixed for the 2021 models, now tow mirrors do power fold on the 1500's (at least for the 5th gens, not sure they updated that on the classics). The other thing you could lose (prior to 2021 MY) is the surround view camera, if the truck would have been optioned with it. However, as mentioned, if you get a 2021 you don't have to worry about losing either of those features.

Hmm. It’s about time somebody in the design department finally decided to pull their head out of their ass and make the tow mirrors foldable with a switch on all models.


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[ramffml]

A weight distribution hitch will help a lot with that but besides that, not everybody who tows is always going to have a loaded truck bed or loaded cab.



Well, I can’t say 100% but I don’t think the 2017 Laramie Longhorn 1500 with air ride that I test drove before I bought my new truck had the 3.21, or not but it sure didn’t feel as peppy to me as the one I got but I guess that’s just me. But see, even though I’m not questioning the validity of your statement but one thing you gotta keep in mind is that everybody’s idea or opinion of a smooth ride or how quick their truck accelerates is a very subjective topic.



The only thing you lack with the tow mirrors is the ability to power fold them.


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A WDH doesn't change your payload. It's required for all 1500's towing >= 5000 pound trailers. Agreed that desired performance is subjective, but we're talking fraction of a second difference in 0 - 60. That's objective.

Given his priorities which explicitly state "maximizing mpg" and "light towing", and given how fast the 3.21 already is... recommending a 3.92 just because you happen to prefer it based on thoughts you thought you had, well, I don't think that helps him but that's just me.

I'm not saying you're nuts for preferring the 3.92, just saying he doesn't need it, and is probably better served by the 3.21

 

[ramffml]

I had 3.42 rear end in my last 1500 truck and in my experience the biggest difference comes when first starting to move from a dead stop and then if you need to move out quickly when cruising on the highway say the quick jump from 60-70 or so. the 3.92 is much quicker than my last truck with 3.42..and with 3.21 I think the difference would be even greater..for all other times..probably no big deal. like others have said, both will do fine, just a personal preference.

This is why I have a hard time believing the 3.92 guys, because they say stuff that can't possibly be true; out on the highway, there is no difference between 3.21 and 3.92. They might be in different numerical gears (6th instead of 7th) but they will be using the same physical gear ratio.

Not ragging on you runamuck, just suggesting that sometimes our internal confirmation bias kicks in (we think it's supposed to be faster so then we notice it's faster when we're driving) and can't be trusted.

 

[Farmer Fran]

Hi everyone,

I am planning on buying a new 2021 RAM 1500 and call me crazy but I would like to achieve the best mileage possible with a V8... (really not sure about the diesel and noise, and $$$)
#1 Priority is the most quiet best riding 4x4, without paying a fortune and able to achieve the best mileage possible. Priority #2 - I won't be towing much maybe a small 2 person fishing boat short distances or a small trailer to haul stuff...under 100 miles.
Here is what I am looking at:
1500 Laramie (need me some cooled seats), Sport, V8, Laramie 2 package, Multi Function tail gate, anti spin diff, 33 gallon fuel tank, 22 inch tires, tow package.

What do I lose by not going with the 3.92 ? ARE there any other options I should consider?

Thank you!

You lose is towing capacity with the 3.21 but it looks like you do not need towing capacity.

to maximize MPG go 3.21, ditch the 33 tank that is more weight, ditch the 22s that is worse mpg, keep the options and weight to a minimum = better MPG.

But I personally think the 22s on an air suspension ride the best overall on these trucks. But more weight and lower MPG

EDIT: also 2x4 = better MPG but I assume in Indiana that is a no go

 

[corneileous]

A WDH doesn't change your payload. It's required for all 1500's towing >= 5000 pound trailers.

I never said that a weight distribution hitch changes your payload so I don’t know where you got that from. All I said was a weight distribution hitch will put a lot more of the weight back on the trailer thus reducing your tongue weight a little bit which affects your payload when you pull a heavy trailer without one.

Agreed that desired performance is subjective, but we’re talking fraction of a second difference in 0 - 60. That’s objective.

I don’t get what you’re trying to say right here but anyways, it doesn’t even matter anyway because I’ve never owned one of these half-tons that had those higher gears and other than whether or not the truck I said I test drove having the 3:21’s; I don’t know because I didn’t look. All I can say is it didn’t feel as quick as mine but hat’s not what I was focusing on when I drove it. I more interested in seeing how the ride was from the four-corner air ride. But as far as just straight up, empty acceleration, maybe there is hardly any difference but I think common sense says where you’ll feel the difference is in pulling a hill or pulling a loaded trailer.

Given his priorities which explicitly state “maximizing mpg” and “light towing”, and given how fast the 3.21 already is... recommending a 3.92 just because you happen to prefer it based on thoughts you thought you had, well, I don't think that helps him but that's just me.

That’s true, he did state max mpg and light towing but that still doesn’t mean he could change his mind on the power/mpg ratio at some point. Hell, even I myself stated I don’t tow anything heavy enough on a regular basis to justify my lower gears but I’m happy with the trade off for the just-in-case scenario and 18mpg on the highway if I drive conservatively so yes, I do think it helps. Whether my opinion matters to the OP and whether or not it’s useful, that’s for him to decide. After all, this is just a discussion to help him weigh out the options.

I'm not saying you're nuts for preferring the 3.92, just saying he doesn't need it, and is probably better served by the 3.21

And again, you don’t totally know that. People change their mind on **** all the time. At least with the lower gears, you have more options if they ever arise but hey, if someone is that concerned about fuel economy in a pickup then why even look at a Hemi in the first place? If you want excellent mileage and still be able to pull almost as good as a 3:92-geared Hemi, get the EcoDiesel.


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[corneileous]

This is why I have a hard time believing the 3.92 guys, because they say stuff that can't possibly be true; out on the highway, there is no difference between 3.21 and 3.92. They might be in different numerical gears (6th instead of 7th) but they will be using the same physical gear ratio.

Not ragging on you runamuck, just suggesting that sometimes our internal confirmation bias kicks in (we think it's supposed to be faster so then we notice it's faster when we're driving) and can't be trusted.

Again, flatland driving doesn’t count. Hook up to a trailer and that’s when you’ll probably will feel the difference. There’s even people who have stated on here that even with just the truck by itself on a hill, the transmission does a lot more down and up shifting.

But see, you’re doing the same exact thing you’re accusing us 3.92 guys of doing...lol. You wanna believe it so much that your higher-geared truck is no different from ours and then you even commence to lightly accusing us of being full of **** over what we say but you know, it doesn’t matter what you think. If you’re happy with what you got, fine but don’t go acting like you’re trying to tell the OP that you know what you’re talking about amd what’s best for him and that we, don’t. There’s a reason why there’s two different diff gear options for these trucks. If there wasn’t then they’d only offer a 3.73 or something like they did years ago.


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[Farmer Fran]

FACT

3.92 = better 60' times
3.21 = lower RPM at any given gear

So 3.92 will pull better and be faster from a stop
So 3.21 will be at a lower RPM on a highway cruise

there is more but these are simple facts to look at.

 

[corneileous]

FACT

3.92 = better 60' times
3.21 = lower RPM at any given gear

So 3.92 will pull better and be faster from a stop
So 3.21 will be at a lower RPM on a highway cruise

there is more but these are simple facts to look at.

Correct. Pretty much explains why we have two options. Those that want better mileage and those that wanna have the higher trailer tow capability.


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[pacofortacos]

I have 3.92's.

For mpg over 70 mph there is only 1 choice 3.21.
Also for mpg - air ride as it goes into Aero mode at highway speed.
20's over 22's for ride/mpg/cost.

Ave. highway mpg ( Over 70 mph) for 3.92 geared trucks is 17-18 mpg - except for the ones that run on unicorn tears and get 20-22 mpg. Those few lucky people should hold onto those trucks because the vast majority with real 3.92 gears will never see that without a tailwind.

IF your majority of driving is in the 55-60 mph AND under that - 3.92's for the win. They do make for a very pleasant combination under 60 mph and can get good mileage at a steady flat 45-50 mph.
I have seen as high as 28-30 mpg @ 45-50 mph in the Florida Keys - running in 4 cyl mode the whole time

 

[ramffml]

Again, flatland driving doesn’t count. Hook up to a trailer and that’s when you’ll probably will feel the difference. There’s even people who have stated on here that even with just the truck by itself on a hill, the transmission does a lot more down and up shifting.

But see, you’re doing the same exact thing you’re accusing us 3.92 guys of doing...lol. You wanna believe it so much that your higher-geared truck is no different from ours and then you even commence to lightly accusing us of being full of **** over what we say but you know, it doesn’t matter what you think. If you’re happy with what you got, fine but don’t go acting like you’re trying to tell the OP that you know what you’re talking about amd what’s best for him and that we, don’t. There’s a reason why there’s two different diff gear options for these trucks. If there wasn’t then they’d only offer a 3.73 or something like they did years ago.


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With the 3.21 and the 3.92, combined with the zf 8 speed, there is NO difference on the highway. That, is a fact. Do the math, look at the available gear ratios. We've done this ad nauseam on the other forum because people are coming from their background of 4 and 6 speeds and thinking a 3.92 is still significantly different in our new 8 speeds. It's not. Gear ratio = Gear ratio.

If my truck is pulling in 7th gear on the freeway, my gear ratio = 2.6322
Your truck will be in 8th, your rpms will ~ equal mine, your gear ratio = 2.5088 (diff of 0.1234)

If my truck is pulling in 6th gear on the freeway, my gear ratio = 3.21.
Your truck will be in 7th, your rpms will ~ equal mine, your gear ratio will be 3.2144 (diff of 0.0044)

If my truck is pulling in 5th gear on the freeway, my gear ratio = 4.2051
Your truck will be in 6th, your rpms will ~ equal mine, your gear ratio will be 3.92 (diff of 0.2851)

So to answer your question, yes, the 3.92 CAN pull more. But it's only really relevant immediately off the line, when both trucks are in first gear. Notice how extremely close those 3 gear ratios are too eachother? You will not notice a difference. Similar numbers for 5 out of the 8 gears.

The 8th gear in 3.21 will downshift on a hill sooner, but that's the entire point of the 3.21, give you that extra gear ratio past the 3.92 to keep your rpms lower on the freeway. If you run into a case where lots of hills give you lots of shifts into 7th, just use the gear limiter and now you're in the same gear as the 3.92 in 8th.

Have you never driven on the freeway in 8th and thought "gee, these rpms are high and this motor has power to spare, I would love another gear"? I bet you have, well that is what the 8th gear in 3.21 feels like. Of course it will have to downshift sooner, but the upside is that you're saving quite a bit of gas.

As for the WDH, I really have no idea why you said what you said about it then; the only thing that matters is that his truck will be payload limited, in either gear ratio. He will not be able to pull a travel trailer > 8000 pounds even WITH the 3.92 because he will be past the payload.


So yes let's summarize:
- his priority is MPG
- he is towing light
- 3.21 can tow up to 8000 pounds
- 3.92 can't realistically tow > 8000 pounds due to payload limitations

Your money your call, but the 3.21 is built for this scenario.

 

[pacofortacos]

Is it even possible to downshift quicker on a hill?
With cruise on and 3.92's, my truck downshifts if it even sees a hill, let alone waiting to lug up it!

 

[runamuck]

This is why I have a hard time believing the 3.92 guys, because they say stuff that can't possibly be true; out on the highway, there is no difference between 3.21 and 3.92. They might be in different numerical gears (6th instead of 7th) but they will be using the same physical gear ratio.

Not ragging on you runamuck, just suggesting that sometimes our internal confirmation bias kicks in (we think it's supposed to be faster so then we notice it's faster when we're driving) and can't be trusted.

well, sorta true..but there is actually no way they would be the same on the highway unless the truck with the 3.21 is in a lower final gear..say 6th..starting out in 1st gear could never be the same because 1st gear x 3.21 will be taller than 1st gear x 3.92. just the way the numbers work out..seat of the pants feel may vary. in the highest gear the 3.21 should top out at a higher speed than the 3.92..if not limited by the computer. the poster above is only right if the trucks are not in the same gear. 8th with a 3.21 just cant be the same as 8th with a 3.92..else folks at the drag strip wasting their time dropping those 3.08's for 4.11's

 

[ramffml]

well, sorta true..but there is actually no way they would be the same on the highway unless the truck with the 3.21 is in a lower final gear..say 6th..starting out in 1st gear could never be the same because 1st gear x 3.21 will be taller than 1st gear x 3.92. just the way the numbers work out..seat of the pants feel may vary. in the highest gear the 3.21 should top out at a higher speed than the 3.92..if not limited by the computer.

They would never be in the same numerical gear (7th and 7th) at the same speed (unless you're manually gear limiting).

But remember, the 3.21 has a "3.21" gear ratio (in 6th). The 3.92 has a "3.2144" gear ratio (in 7th). Therefore if both trucks are travelling at the same speed, they will be using pretty much identical gear ratios, meaning, identical power/torque at that speed. (doesn't matter that the one truck is in 6th and the other in 7th, what matters is the gear ratio, and that's where they are equal).

The math works out in this specific case (zf 8 speed with 3.21 and 3.92) such that there are 5 pretty much identical gear ratios to choose from out on the highway. Then the 3.21 has an extra gear ratio, and the 3.92 has shorter gears around first and second.

So, off the line the 3.92 is going to pull harder. Once the trucks are in 3rd and beyond, there is no difference, they both have nearly identical gear ratios to choose from, just offset by one numerical gear number.

 

[runamuck]

I have 3.92's.

For mpg over 70 mph there is only 1 choice 3.21.
Also for mpg - air ride as it goes into Aero mode at highway speed.
20's over 22's for ride/mpg/cost.

Ave. highway mpg ( Over 70 mph) for 3.92 geared trucks is 17-18 mpg - except for the ones that run on unicorn tears and get 20-22 mpg. Those few lucky people should hold onto those trucks because the vast majority with real 3.92 gears will never see that without a tailwind.

IF your majority of driving is in the 55-60 mph AND under that - 3.92's for the win. They do make for a very pleasant combination under 60 mph and can get good mileage at a steady flat 45-50 mph.
I have seen as high as 28-30 mpg @ 45-50 mph in the Florida Keys - running in 4 cyl mode the whole time

sticking to the results I have had with my own..almost always get around 20 on trips and nearly always cruise at 70-75..maybe just luck of the draw..not really many roads you can mosey along at 55-60 around here but I do tend to only travel at 68-69 when towing..

 

[Farmer Fran]

With the 3.21 and the 3.92, combined with the zf 8 speed, there is NO difference on the highway. That, is a fact. Do the math, look at the available gear ratios. We've done this ad nauseam on the other forum because people are coming from their background of 4 and 6 speeds and thinking a 3.92 is still significantly different in our new 8 speeds. It's not. Gear ratio = Gear ratio.

If my truck is pulling in 7th gear on the freeway, my gear ratio = 2.6322
Your truck will be in 8th, your rpms will ~ equal mine, your gear ratio = 2.5088 (diff of 0.1234)

If my truck is pulling in 6th gear on the freeway, my gear ratio = 3.21.
Your truck will be in 7th, your rpms will ~ equal mine, your gear ratio will be 3.2144 (diff of 0.0044)

If my truck is pulling in 5th gear on the freeway, my gear ratio = 4.2051
Your truck will be in 6th, your rpms will ~ equal mine, your gear ratio will be 3.92 (diff of 0.2851)

So to answer your question, yes, the 3.92 CAN pull more. But it's only really relevant immediately off the line, when both trucks are in first gear. Notice how extremely close those 3 gear ratios are too eachother? You will not notice a difference. Similar numbers for 5 out of the 8 gears.

The 8th gear in 3.21 will downshift on a hill sooner, but that's the entire point of the 3.21, give you that extra gear ratio past the 3.92 to keep your rpms lower on the freeway. If you run into a case where lots of hills give you lots of shifts into 7th, just use the gear limiter and now you're in the same gear as the 3.92 in 8th.

Have you never driven on the freeway in 8th and thought "gee, these rpms are high and this motor has power to spare, I would love another gear"? I bet you have, well that is what the 8th gear in 3.21 feels like. Of course it will have to downshift sooner, but the upside is that you're saving quite a bit of gas.

As for the WDH, I really have no idea why you said what you said about it then; the only thing that matters is that his truck will be payload limited, in either gear ratio. He will not be able to pull a travel trailer > 8000 pounds even WITH the 3.92 because he will be past the payload.


So yes let's summarize:
- his priority is MPG
- he is towing light
- 3.21 can tow up to 8000 pounds
- 3.92 can't realistically tow > 8000 pounds due to payload limitations

Your money your call, but the 3.21 is built for this scenario.

Do me a favor and pull the RPM maps up and post them side by side. 3.21 with 8speed and 3.92 vs 8speed.

The 3.21 will ALWAYS be at lower rpm at speed in the same gear. FACT

 

[ramffml]

Do me a favor and pull the RPM maps up and post them side by side. 3.21 with 8speed and 3.92 vs 8speed.

The 3.21 will ALWAYS be at lower rpm at speed in the same gear. FACT

Exactly. But they won't be in the same (numerical) gear. They will be in the same gear ratio though.

 

[Dodge 1500 4X4]

FACT

3.92 = better 60' times
3.21 = lower RPM at any given gear

So 3.92 will pull better and be faster from a stop
So 3.21 will be at a lower RPM on a highway cruise

there is more but these are simple facts to look at.

And lower RPM's for the 3:21 means the engine lasting longer, continuous high RPM's are not good for these engines.