3.92 vs 3.21 Who Wins? TruckTrend data shows...

[robbiele]

(I TOOK THIS FROM SOMEBODY ELSE FROM ANOTHER FORUM, BUT IT DEFINITELY INTERESTS ME)

Source: TruckTrend's 2019 Pickup Truck of the Year contest
Article: TruckTrend's "Running The Gauntlet" 2019 March/April Issue
3.92- 2019 Ram 1500 Rebel 4X4

• Engine: 5.7L V8 w/ eTorque
• Weight: 5,534 lbs
• Tires: LT275/70R18
• Fuel Capacity: 33 GAL
• Tire Diameter (via online calculator): 33.2 in

3.21- 2019 Ram 1500 Laramie Longhorn 4X4

• Engine: 5.7L V8 w/ eTorque
• Weight: 5,652 lbs
• Tires: P275/55R20
• Fuel Capacity: 33 GAL
• Tire Diameter (via online calculator): 31.9 in

STATS (Winner highlighted in Green)

• Accel 0-60 MPH 3.92- 6.94 secs; 3.21- 6.44 secs
• 1/4 Mile 3.92- 15.93 secs @ 91.13 MPH; 3.21- 15.71 secs @ 92.97 MP
• Accel 0-60 (Towing 7,500 lb weight) 3.92- 14.28 secs; 3.21- 14.48 secs
• 1/4 Mile (Towing 7,500 lb weight) 3.92- 20.23 secs @ 72.57 MPH; 3.21- 20.30 secs @ 72.95 MPH
• Tested Fuel Econ (Average/Best) 3.92- 14.50/17.96; 3.21- 15.73/19.07

My thoughts...
While this is not a 100% apples-to-apples axle ratio comparison between two Ram trucks, it does offer some insight between the 3.92 and 3.21 ratios. For acceleration tests, my money would have been on the 3.92 truck that tipped the scales at 118 lbs lighter, but the results were almost evenly matched. It's quite possible that the 33.2 in tires on the 3.92 truck actually changed the effective axle ratio closer to that of the 3.21 with 31.9 in tires.


The biggest difference between the two trucks was seen in the average and best fuel economy observed in TruckTrend's test. The 3.21 achieved 1.23 MPG better on average and its best fuel economy was 1.11 MPG better that the 3.92.

 

[Ramlax]

(I TOOK THIS FROM SOMEBODY ELSE FROM ANOTHER FORUM, BUT IT DEFINITELY INTERESTS ME)

Source: TruckTrend's 2019 Pickup Truck of the Year contest
Article: TruckTrend's "Running The Gauntlet" 2019 March/April Issue
3.92- 2019 Ram 1500 Rebel 4X4

• Engine: 5.7L V8 w/ eTorque
• Weight: 5,534 lbs
• Tires: LT275/70R18
• Fuel Capacity: 33 GAL
• Tire Diameter (via online calculator): 33.2 in

3.21- 2019 Ram 1500 Laramie Longhorn 4X4

• Engine: 5.7L V8 w/ eTorque
• Weight: 5,652 lbs
• Tires: P275/55R20
• Fuel Capacity: 33 GAL
• Tire Diameter (via online calculator): 31.9 in

STATS (Winner highlighted in Green)

• Accel 0-60 MPH 3.92- 6.94 secs; 3.21- 6.44 secs
• 1/4 Mile 3.92- 15.93 secs @ 91.13 MPH; 3.21- 15.71 secs @ 92.97 MP
• Accel 0-60 (Towing 7,500 lb weight) 3.92- 14.28 secs; 3.21- 14.48 secs
• 1/4 Mile (Towing 7,500 lb weight) 3.92- 20.23 secs @ 72.57 MPH; 3.21- 20.30 secs @ 72.95 MPH
• Tested Fuel Econ (Average/Best) 3.92- 14.50/17.96; 3.21- 15.73/19.07

My thoughts...
While this is not a 100% apples-to-apples axle ratio comparison between two Ram trucks, it does offer some insight between the 3.92 and 3.21 ratios. For acceleration tests, my money would have been on the 3.92 truck that tipped the scales at 118 lbs lighter, but the results were almost evenly matched. It's quite possible that the 33.2 in tires on the 3.92 truck actually changed the effective axle ratio closer to that of the 3.21 with 31.9 in tires.


The biggest difference between the two trucks was seen in the average and best fuel economy observed in TruckTrend's test. The 3.21 achieved 1.23 MPG better on average and its best fuel economy was 1.11 MPG better that the 3.92.

This is very interesting good article, makes me not regret my 3.21 gear choice

 

[Neurobit]

Thanks for posting this.
Love my 3.21. No regrets whatsoever. I’ve never had any issues being unhappy with acceleration etc.

 

[Billy James]

The tire size does make these two drive ratios closer. Just doing "quick math" without any complicated formulas, with those sizes, the Rebel effective drive ratio would be knocked down to about 3.766. My hunch is that a difference in tire weight/rotational mass is what we are seeing. The LT275/70R18 Falken AT3/W weighs 61 pounds; the Bridgestone Dueler H/L P275/55R20 (like on my Laramie) weighs 41 pounds. I would bet if you took two similarly equipped trucks with the same tires and wheels (one with 3.21 and the other with 3.92 gears) then the results would be reversed and by a wider margin. If anything; this should prove why you should get 3.92 gears if you ever want to get bigger off road tires. Interesting though; I had to go read the article and see for myself. One point that is not made here is towing capacity: Longhorn 3.21 = 8,150 / Rebel 3.92 = 11,330.

 

[robbiele]

The tire size does make these two drive ratios closer. Just doing "quick math" without any complicated formulas, with those sizes, the Rebel effective drive ratio would be knocked down to about 3.766. My hunch is that a difference in tire weight/rotational mass is what we are seeing. The LT275/70R18 Falken AT3/W weighs 61 pounds; the Bridgestone Dueler H/L P275/55R20 (like on my Laramie) weighs 41 pounds. I would bet if you took two similarly equipped trucks with the same tires and wheels (one with 3.21 and the other with 3.92 gears) then the results would be reversed and by a wider margin. If anything; this should prove why you should get 3.92 gears if you ever want to get bigger off road tires. Interesting though; I had to go read the article and see for myself. One point that is not made here is towing capacity: Longhorn 3.21 = 8,150 / Rebel 3.92 = 11,330.

I would love to see this kind of test done with similar specs as to tires etc and not using the rebel or off road package

 

[Electrical]

Your 0 to 60 numbers don't match the article: http://www.trucktrend.com/truck-of-the-year/1812-pickup-truck-of-the-year-winner-2019-ram-1500/

 

[Lateralus]

... shows nothing.

 

[Billy James]

Your 0 to 60 numbers don't match the article: http://www.trucktrend.com/truck-of-the-year/1812-pickup-truck-of-the-year-winner-2019-ram-1500/

Good catch...looks like only a .01 difference in the article with the Rebel 3.92 having the edge.

 

[robbiele]

Your 0 to 60 numbers don't match the article: http://www.trucktrend.com/truck-of-the-year/1812-pickup-truck-of-the-year-winner-2019-ram-1500/

Good. I am interested in a 3.92 and this seemed off to me as well

 

[ChadT]

33.2in mud terrain tires
1in lift
no air dam, ground clearance oriented fascia
Skidplates gallore underneath?

I for one am shocked, totally shocked, it wasn't great at the drag strip!
3.92 axle isn't a big enough band aid for the above.

 

[rsonedecker]

• Accel 0-60 MPH 3.92- 6.94 secs; 3.21- 6.44 sec.

According to the article, these are the correct times:

Accel 0-60 MPH 3.92- 7.54 secs; 3.21- 7.53 sec.

 

[Bleda2002]

According to the article, these are the correct times:

Accel 0-60 MPH 3.92- 7.54 secs; 3.21- 7.53 sec.

That's still backwards,

The 3.92 was 7.53, the 3.21 was 7.54

 

[Bhbdvm]

Interesting. I'm no a rocket scientist but I do know the tremendous effects that rotational mass can have on acceleration. Larger heavier tires make a tremendous difference in getting off the line and maintaining speed. Aerodynamics also plays a big role. I didn't get my 3.92 to race, I got it to help tow. Bottom line, if I had bigger tires and raced a 3.21 looks like I could get beat )

 

[SpeedyV]

Interesting. I'm no a rocket scientist but I do know the tremendous effects that rotational mass can have on acceleration. Larger heavier tires make a tremendous difference in getting off the line and maintaining speed. Aerodynamics also plays a big role. I didn't get my 3.92 to race, I got it to help tow. Bottom line, if I had bigger tires and raced a 3.21 looks like I could get beat )

Haha, true...even lifted diesels are sluggish!

 

[Electrical]

All things equal, the 3.92 sprints to 60 quicker.

But after 1,300 feet the 3.21 has caught up and begins pulling away. Look at the difference in speed at the end of the quarter.

 

[I_really_really_want_one!]

This is silly. Put the same tires and ride height on each and retest. My money is on the 3.92 for performance and the 3.21 for economy.

If you need to tow more than 4 tons or want to tool around on big tires you've got one choice - 3.92. On the other hand if you don't have those requirements and want to save some scratch 3.21.

Anyone know if we can you order with the 3.55 yet? For a bunch of us that would be the best choice.

 

[ChadT]

That's still backwards,

The 3.92 was 7.53, the 3.21 was 7.54

So 3.92 was still faster?
Not bad considering these



are basically the total opposite of these


Not at all insignificant when the comparison in question is a literal drag race.

So the takeaways appear to be:
- Yes 3.92 is more desirable for towing, acceleration, and larger tires
- No, having 3.21 gears on your truck won't turn it into an undriveable snail that's so bad you need to sell it and trade it in for an identical 3.92 truck.
- Have 3.21 gears? Don't tow? You don't have huge mud terrains on it? Don't worry about it.

 

[ChadT]

Accidental doublepost

 

[devildodge]

Anyone know if we can you order with the 3.55 yet? For a bunch of us that

Sure, you can get 3.55 on the V6

I do not believe 3.55 will be available on the V8...but you never know.

 

[19llhpb]

This is silly. Put the same tires and ride height on each and retest. My money is on the 3.92 for performance and the 3.21 for economy.

If you need to tow more than 4 tons or want to tool around on big tires you've got one choice - 3.92. On the other hand if you don't have those requirements and want to save some scratch 3.21.

Anyone know if we can you order with the 3.55 yet? For a bunch of us that would be the best choice.

Well said and simple, that is 100% it and over on the 3:21 vs 3:92 debate. And yes I agree, seems if the 3:55 was available with the Hemi that would satisfy the majority.