3.21 vs 3.92: The Last Word

[Dewey]

Sounds like we need some more math...

Math is for people with no common sense.

 

[ferraiolo1]

I’ll do the math………

3.21’s @ 80 mph=1800 rpm’s
3.92’s @ 80 mph=2200 rpm’s

An extra 400 rpm’s is required to produce the same hp from the same motor. Extra rpm’s mean more fuel used.

If you like to drive fast and don’t tow much the choice is easy.

Enjoy

I think sb has a setting to where he can’t see when posts with factual info are produced!


Sent from my iPhone using Tapatalk

 

[SnowBlaZR2]

I think sb has a setting to where he can’t see when posts with factual info are produced!


Sent from my iPhone using Tapatalk

I saw it, but I don't drive 80 mph very often. Even if I did, potentially saving $6-8 per week (we know it probably isnt even that much ) isn't as important to me as having a more capable truck when I need it.

 

[Mountain Whiskey]

All that math and it is still the same outcome. 3.92 gears are the right gears for a capable versatile truck.

 

[ferraiolo1]

Except when you want to get good mpg at sustained highway speeds.


Sent from my iPhone using Tapatalk

 

[SnowBlaZR2]

20.5 mpg is good...

 

[djevox]

30 is better.

 

[SnowBlaZR2]

30 is better.

Well, since everyone was recommending going up to a 3500 to tow up hills...

 

[Dewey]

If your worried if your truck can tow or not you might want a REAL truck.

 

[StuartV]

20.5 mpg is good...

I would love to get that. I have 67K miles on my 2019 1500 - with 3.92 gearing and a Hemi with e-Torque. That is in less than 3 years since I bought it. I have tracked every fill-up in Fuelly (a smarthphone app) since I bought the truck. The best mileage I have ever gotten was 20.0 MPG on one tank. My average over the whole 67K miles is 14.0 MPG. And I work from home, so my mileage is mostly highway miles.

My next truck will have 3.21 gearing. And I'm pretty sure that will save me more than $6-8 a week.

 

[SnowBlaZR2]

I would love to get that. I have 67K miles on my 2019 1500 - with 3.92 gearing and a Hemi with e-Torque. That is in less than 3 years since I bought it. I have tracked every fill-up in Fuelly (a smarthphone app) since I bought the truck. The best mileage I have ever gotten was 20.0 MPG on one tank. My average over the whole 67K miles is 14.0 MPG. And I work from home, so my mileage is mostly highway miles.

If you're at 14 mpg, a new rear end isn't going to bump you up 6.5 mpg. Maybe 2 mpg or so, if you order essentially the same truck and maintain the same driving habits along the same route for the same mileage.

You want better fuel economy? Use your right foot less.

My next truck will have 3.21 gearing. And I'm pretty sure that will save me more than $6-8 a week.

OK, for you maybe $10-12 because you drive more than average. You could argue that fuel prices will remain high and that will have some effect, but we should probably stick to the numbers we have.

Either way, all you're really doing here is supporting a point I've made several times in these threads. If a Maverick or a Frontier would be more than enough truck for you and you just want something bigger, go for it.

 

[theblet]

If you're at 14 mpg, a new rear end isn't going to bump you up 6.5 mpg. Maybe 2 mpg or so, if you order essentially the same truck and maintain the same driving habits along the same route for the same mileage.

You want better fuel economy? Use your right foot less.

OK, maybe $10-12 because you drive more than average. You could argue that fuel prices will remain high and that will have some effect, but we should probably stick to the numbers we have.

Either way, all you're really doing here is supporting a point I've made several times in these threads. If a Maverick or a Frontier would be more than enough truck for you and you just want something bigger, go for it.

But if you get a maverick or a frontier, you won’t have a Ram anymore.

 

[SnowBlaZR2]

But if you get a maverick or a frontier, you won’t have a Ram anymore.

Someone has to buy them. I can't think of a better customer for a Ford Maverick than the guy who buys a Ram with 3.21s on purpose, knowing there's a better option.

 

[theblet]

Someone has to buy them. I can't think of a better customer for a Ford Maverick than the guy who buys a Ram with 3.21s on purpose, knowing there's a better option.

Its definitely not a better option. I’d rather have a ram with 2.83 gears than those trucks

 

[SnowBlaZR2]

Its definitely not a better option. I’d rather have a ram with 2.83 gears than those trucks

Oh no, I'm not saying it's a better option. I'd push my Ram down the road before I bought one.

 

[Mountain Whiskey]

I would love to get that. I have 67K miles on my 2019 1500 - with 3.92 gearing and a Hemi with e-Torque. That is in less than 3 years since I bought it. I have tracked every fill-up in Fuelly (a smarthphone app) since I bought the truck. The best mileage I have ever gotten was 20.0 MPG on one tank. My average over the whole 67K miles is 14.0 MPG. And I work from home, so my mileage is mostly highway miles.

My next truck will have 3.21 gearing. And I'm pretty sure that will save me more than $6-8 a week.

I have to agree with @SnowBlaZR2 that you won't make up over 6 mpg with a gear change to 3.21.

I don't see a mention of a lift or oversized tires in your signature. What are you doing to get 14mpg? I get just over 14 driving 50 miles each way to work. That is some country road out to highway traffic around 80 mph then a bit of city. So a fair mix.

I drive hard and have a lift and 35s. You would think you get better milage than me.

 

[Gitter]

I would love to get that. I have 67K miles on my 2019 1500 - with 3.92 gearing and a Hemi with e-Torque. That is in less than 3 years since I bought it. I have tracked every fill-up in Fuelly (a smarthphone app) since I bought the truck. The best mileage I have ever gotten was 20.0 MPG on one tank. My average over the whole 67K miles is 14.0 MPG. And I work from home, so my mileage is mostly highway miles.

My next truck will have 3.21 gearing. And I'm pretty sure that will save me more than $6-8 a week.

Yeah, you have something else going on (a heavy foot, big wheels, or a drogue parachute?) and switching to 3.21 probably won't to help you as well as you think it will.

I have heavy e-rated 34" tires and a lift/air-link level kit on my 2020 w/ 3.92, Hemi, & e-Torque along with all of the other options your signature is showing. I put the tires on after only 1K on the truck, so I have 21K miles with these tires and I average 15-16 MPGs. Before the tires went on, I was averaging 17 MPGs. This is while doing a 60/40 (city/highway) mix of driving...and I'm not a slow driver at all. lol

 

[StuartV]

If you're at 14 mpg, a new rear end isn't going to bump you up 6.5 mpg. Maybe 2 mpg or so, if you order essentially the same truck and maintain the same driving habits along the same route for the same mileage.

You want better fuel economy? Use your right foot less.

OK, for you maybe $10-12 because you drive more than average. You could argue that fuel prices will remain high and that will have some effect, but we should probably stick to the numbers we have.

Either way, all you're really doing here is supporting a point I've made several times in these threads. If a Maverick or a Frontier would be more than enough truck for you and you just want something bigger, go for it.

I never said it would bump me up 6.5 MPG. I said I think it will save me more than $6-8 per week (the numbers you posted). And apparently, we agree on that.

If something smaller would work for me, I would consider it. But, I frequently have my truck loaded so full of scuba gear that a smaller vehicle would not work for me. Plus, there is the occasional need to tow a large pontoon boat 2 miles from the shop to the lake (which 3.21 gears would be fine for - you should see the other vehicles we tow the boats with!). And then there is also the occasional need to haul one of my motorcycles somewhere. My KTM is so big, I don't think it would fit in a Maverick, even at an angle. But, I could be wrong about that.

Sorry. Trying to imply I don't need a 1/2 ton truck doesn't work. I just don't need it to have more towing capability than 3.21 gears would give.

I have to agree with @SnowBlaZR2 that you won't make up over 6 mpg with a gear change to 3.21.

I don't see a mention of a lift or oversized tires in your signature. What are you doing to get 14mpg? I get just over 14 driving 50 miles each way to work. That is some country road out to highway traffic around 80 mph then a bit of city. So a fair mix.

I drive hard and have a lift and 35s. You would think you get better milage than me.

Where did I say I would get 6 MPG improvement?? (Answer: Nowhere) I did say I would love to get 20.5 MPG - but I know that's not going happen. I also said I think I could save more the $6-8 per week with 3.21.

I have had 33" (P285) tires on 20" wheels since my stock tires wore out. So, a bit over half of my truck's life. I have not had my speedo/odo recalibrated. But, 33s are not enough bigger than the stock tires to make THAT much difference on the calibration, I don't think. I believe the stock tires were 32". So, a 1/2 inch bigger rolling radius? That's 3% bigger. So, maybe my actual mileage is 3% higher than what Fuelly says. 14.2MPG, instead of 14 (assuming I had bigger tires for half my total miles).

I DO drive with a heavy foot. I use the Adaptive Cruise ALL the time (in town and on the highway), and I have verified that it does result in roughly 1 MPG less fuel economy than using regular Cruise. And, I have racked up so many miles by doing a LOT of highway driving on Interstates (drive to dive). I typically run 10 MPH over the limit. Occasionally, 15. So, a LOT of miles with the Adaptive cruise set at 80 (or sometimes 85). Even with the air suspension at "Aero Ride Height", those speeds put a serious hurting on mileage.

Yeah, you have something else going on (a heavy foot, big wheels, or a drogue parachute?) and switching to 3.21 probably won't to help you as well as you think it will.

I have heavy e-rated 34" tires and a lift/air-link level kit on my 2020 w/ 3.92, Hemi, & e-Torque along with all of the other options your signature is showing. I put the tires on after only 1K on the truck, so I have 21K miles with these tires and I average 15-16 MPGs. Before the tires went on, I was averaging 17 MPGs. This is while doing a 60/40 (city/highway) mix of driving...and I'm not a slow driver at all. lol

I am just GUESSING I will get about 2 MPG better with 3.21. Which would be a 14% improvement. With no downside (for ME). I don't need to tow anything that is heavier than what 3.21 will handle. I'll happily take a 14% improvement in my gas bill. I have spent $12,421.58 on gas for my truck in less than 3 years. 14% of that would be $1,700+, and the savings are only getting bigger as gas prices go up.

I did tow a cargo trailer from northern VA here to SC last year when I moved. I stopped and weighed my rig on the way down. CAT scales ticket said 17,100 #, total, truck and trailer combined. I knew I was heavy, but I didn't know I was THAT heavy until it was too late to do anything but finish the drive and get it unloaded. I will NEVER do that again - no matter what rear end I have. It was only an 18' bumper pull trailer, but I have a lot of shop tools...

Regardless, I feel pretty confident that a Hemi with eTorque and 3.21 gears still could have gotten that rig moving. And, once you're past walking speed(-ish), it doesn't matter. It's the stopping and turning that is the issue and 3.92 gearing ain't gonna help with that.

 

[bigdodge]

I have to hand it to the posters who write a book supporting their views when it means nothing as we get what we want!

 

[SnowBlaZR2]

I never said it would bump me up 6.5 MPG. I said I think it will save me more than $6-8 per week (the numbers you posted). And apparently, we agree on that.

Neat, I'm just telling you that you're dreaming. And sure, we agree on that because I did the math based on averages. A better way to put it would've been you'd save maybe $0.02 per mile.

If you want to save money on gas, driving the truck less, using the accelerator less, getting a more fuel efficient vehicle, etc are all going to have a bigger impact than going with a 3.21 rear end. Do what you want, but don't try to blow smoke about the huge fuel savings.

Sorry. Trying to imply I don't need a 1/2 ton truck doesn't work. I just don't need it to have more towing capability than 3.21 gears would give.

Well, it does work. A 1/2 ton truck just works better.

Kind of like 3.21s work, but 3.92s work better.