An Engineer's Ultimate Guide To 3.21 VS 3.92 Axle Ratio

[SnowBlaZR2]

Well, at least you got the right sized gas tank. yea, I went there......

 

[TNRamGuy]

F*ing aw*m.

 

[ferraiolo1]

It depends on your spare tire and payload


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[TNRamGuy]

Omg, I really want to sit around with you guys, a few bottles, and just hash things out...

 

[nc_beagle]

Maybe his tires suck? In all "seriousness" for a second, I'm totally happy with the 3.21. I think the truck has plenty of power, especially considering that I drive not in a hurry everywhere I go. Now, if I was doing significant towing I'd have a different opinion, but just driving the truck day to day, I don't think there's a significant gain for me to have "justified" 3.92's. I mean, I'm not in the habit of cutting people off, but I don't think these trucks have real issues getting up to speed.

I've jumped into the banter a few times, but I'd probably have been happy with the 3.21 given that I don't see us upsizing our camper any time soon. I think I was mostly drawn into the roughly 2K tow rating difference, figuring it just might be possible I need to tow over 8K at some point. I suppose had there been a middle choice, that's the one I'd have taken. Get a little better mileage on the interstate and lose say 1K of tow rating.

 

[KWKSLVR]

I've jumped into the banter a few times, but I'd probably have been happy with the 3.21 given that I don't see us upsizing our camper any time soon. I think I was mostly drawn into the roughly 2K tow rating difference, figuring it just might be possible I need to tow over 8K at some point. I suppose had there been a middle choice, that's the one I'd have taken. Get a little better mileage on the interstate and lose say 1K of tow rating.

Oh, if I had planned on any towing at all I'd have done 3.92s. I'll have a small 4 wheeler in the back from time to time and I might have a few 3000-4000lb tows but that's about it. My max tow is 7831. I can't imagine needing to do more than 5500. I'm just playing my most use case.

 

[SnowBlaZR2]

Oh, if I had planned on any towing at all I'd have done 3.92s. I'll have a small 4 wheeler in the back from time to time and I might have a few 3000-4000lb tows but that's about it. My max tow is 7831. I can't imagine needing to do more than 5500. I'm just playing my most use case.

I tow about 3700 lbs and still went with 3.92s because I didn't let my wife build my truck for me.

 

[TNRamGuy]

The old ram and the 3.21 ram were standing at the top of the hill overlooking a paddock of many gorgeous young sheep. The 3.21 ram said, "Let's charge down the hill, knock over that fence and service one of those sheep each". The old ram wisely replied, "Why don't we saunter down the hill, open the gate, take a sip at the water trough and then service ALL of those sheep"

 

[The Hound 2021]

I've jumped into the banter a few times, but I'd probably have been happy with the 3.21 given that I don't see us upsizing our camper any time soon. I think I was mostly drawn into the roughly 2K tow rating difference, figuring it just might be possible I need to tow over 8K at some point. I suppose had there been a middle choice, that's the one I'd have taken. Get a little better mileage on the interstate and lose say 1K of tow rating.

Diesels don't count. Sorry.

 

[TNRamGuy]

I've jumped into the banter a few times, but I'd probably have been happy with the 3.21 given that I don't see us upsizing our camper any time soon. I think I was mostly drawn into the roughly 2K tow rating difference, figuring it just might be possible I need to tow over 8K at some point. I suppose had there been a middle choice, that's the one I'd have taken. Get a little better mileage on the interstate and lose say 1K of tow rating.

Wow, Switzerland, no there is no middle ground, 3.92 rules

 

[1ramrunner]

I am still torn, my truck has 3.92 and gets about 15 mpg, my car has 3.23 and I'm lucky to get 15 mpg. The truck has the old 5-speed auto and the car has the old 4-speed manual. It would help if the truck was the new 8-speed and the car was the new 6-speed. My truck doesn't tow, but my car does haul. Thinking 3.21 for the new truck, and 6-speed for the extra car.

 

[m.hamner]

I am still torn, my truck has 3.92 and gets about 15 mpg, my car has 3.23 and I'm lucky to get 15 mpg. The truck has the old 5-speed auto and the car has the old 4-speed manual. It would help if the truck was the new 8-speed and the car was the new 6-speed. My truck doesn't tow, but my car does haul. Thinking 3.21 for the new truck, and 6-speed for the extra car.

I just don't really see myself towing more than 6k lbs, and that's like once or twice a year for a week or so, max. Realistically, it will probably be around 4.5k of towing. I just think if all this concern is for towing, the 2500 is probably the way to go. That way, you've got the payload, the towing, and the bigger brakes, beefier frame, etc.

I googled campers that I can tow with my 3.21's and came across this camper. https://www.jayco.com/rvs/travel-trailers/2022-jay-flight-slx-8/264bh/ it sleeps up to 9 and is between 4500lbs and I'm telling you, if I can haul this with 3.21's, this gear ratio is more than enough to be my daily driver on the highway and save a few bucks every once in a while if I wanna baby it. Well within spec.

 

[SnowBlaZR2]

I just don't really see myself towing more than 6k lbs, and that's like once or twice a year for a week or so, max. Realistically, it will probably be around 4.5k of towing. I just think if all this concern is for towing, the 2500 is probably the way to go. That way, you've got the payload, the towing, and the bigger brakes, beefier frame, etc.

I googled campers that I can tow with my 3.21's and came across this camper. https://www.jayco.com/rvs/travel-trailers/2022-jay-flight-slx-8/264bh/ it sleeps up to 9 and is between 4500lbs and I'm telling you, if I can haul this with 3.21's, this gear ratio is more than enough to be my daily driver on the highway and save a few bucks every once in a while if I wanna baby it. Well within spec.

I'd bet the tongue weight of that trailer would cause you some payload problems. You're going to be pushing well past 600 lbs and maybe closing on 700 lbs when you load it up.

 

[m.hamner]

I'd bet the tongue weight of that trailer would cause you some payload problems. You're going to be pushing well past 600 lbs and maybe closing on 700 lbs when you load it up.

Shouldn’t it be 450-500? 10% of the total?

 

[saulster]

Mine ( 2021 1500 Limited Eco ) has the 3.21s and seems plenty lively to me. Since I don't plan much if any towing, I like the much lower RPMs, especially at cruising speeds on the highway.

That said, if the highway is going uphill a bit, it usually downshifts to accommodate. In those places, with the downshift, I might be seeing the same or close to the same RPMs as the 3.92 without downshift. But then when things level out or go downhill, I see much less RPMs. Works for me. But if I was towing regularly, that would be another consideration.

So far in about 2K miles, averaging 23 MPG. ( The gauge usually says 24.5 to 25.5 average, it is quite optimistic! ) No longer trips yet, I will be interested to see how much improvement I get with long highway cruising.

 

[SnowBlaZR2]

Shouldn’t it be 450-500? 10% of the total?

Jayco says it's 470 dry, which is right around where mine was listed. Shipped, our tongue weight came it at 524 lbs. That 4580 lbs is also for a bone dry and stripped trailer. Add any options, propane, cargo, and anything in the tanks and that number goes up quick.

You might be able to balance it out to get closer to 10% on the tongue, but I'd bet you'd probably end up around 12%.

Your truck also has a lot of heavy options, so you're probably looking at under 1200 lbs payload. Maybe less. I'm just saying that gears probably won't be your bottleneck when towing.

 

[m.hamner]

Jayco says it's 470 dry, which is right around where mine was listed. Shipped, our tongue weight came it at 524 lbs. That 4580 lbs is also for a bone dry and stripped trailer. Add any options, propane, cargo, and anything in the tanks and that number goes up quick.

You might be able to balance it out to get closer to 10% on the tongue, but I'd bet you'd probably end up around 12%.

Your truck also has a lot of heavy options, so you're probably looking at under 1200 lbs payload. Maybe less. I'm just saying that gears probably won't be your bottleneck when towing.

You're definitely right about that. I don't even need a trailer that big. Just one that sleeps 5! ha!

 

[SnowBlaZR2]

You're definitely right about that. I don't even need a trailer that big. Just one that sleeps 5! ha!

I'd get one that sleeps two and put the kids in a tent lol.

 

[TNRamGuy]

I'd get one that sleeps two and put the kids in a tent lol.

I would get a toy hauler, wife in tent, and kids are great stewed!

 

[Eighty]

Lol, you guys talk a good game. Say that **** with your wives standing there, and let’s see how things go!