So, I’ve read all the posts here related to the 3.21 vs 3.92, but now have back-to-back, real world experience with both. Here’s the result:
Buy the 3.92 if:
- you are going to tow more than 8,000 lbs
- you are going to put big tires on
- you need a rock-crawling 1st gear
- you really don’t care how much you spend on gas
- you just have to have the 3.92, for rational or other reasons
If none of the above, buy the 3.21. I just spent a week and 600 mi with a brand new 2020 1500 DT Laramie 5.7 non-etorque 3.21 and the the next 600mi week with same brand new truck but e-torque 3.92 (that I had ordered a month earlier).
As for the usual reasons to buy a 3.92:
- acceleration: yes the 3.92 is a little more perky feeling, but the 3.21 is plenty quick. In fact, the 3.92 1st gear is so low,you’ll be well into 3rd before you hit 60. The 3.21 hits 60 right after shifting into 3rd.
- towing: for trailers at or under 8k, the 3.21 is fine. Yes it will operate one one gear lower pretty much the whole time, and be a little slower from a stop, but easily plenty of power.
- load capacity: no difference, so not a factor
I ordered and took delivery of the 3.92, and while it’s fine, had I ordered after having the 3.21, I probably would have gone 3.21. My travel trailer is around 6300#, and either works.
MPG wise, the 3.21 averaged almost 2 mpg better. I do 80/20 highway/city by miles, but 50/50 by time, and the 3.92 mileage is notably worse at stop&go and at speeds over 70. (should note the 3.92 truck was a couple hundred pounds heavier). The 3.92 turns 1980 RPM at 70, while the 3.21 does 1620. Excluding towing, I’m averaging 18 in the 3.92 etorque so far.
That all said, the 3.92 should be a tiny bit easier to sell, as it can do everything (except get better mileage). while some buyers will avoid 3.21 trucks.
Also, the 3.21 truck downshifts from 8th much more readily, and seems to come out of ECO more readily. (working on another info post, on reverse engineering the criteria for entering/exiting ECO).
Side note, I like the eTorque, and am not bothered by ECO or Stop-Start. I would definitely buy etorque again.
Anyhow, I quite like my truck so far, and am not trading it for a 3.21, but figured I’d pass on these observations for those considering their options.
Buy the 3.92 if:
- you are going to tow more than 8,000 lbs
- you are going to put big tires on
- you need a rock-crawling 1st gear
- you really don’t care how much you spend on gas
- you just have to have the 3.92, for rational or other reasons
If none of the above, buy the 3.21. I just spent a week and 600 mi with a brand new 2020 1500 DT Laramie 5.7 non-etorque 3.21 and the the next 600mi week with same brand new truck but e-torque 3.92 (that I had ordered a month earlier).
As for the usual reasons to buy a 3.92:
- acceleration: yes the 3.92 is a little more perky feeling, but the 3.21 is plenty quick. In fact, the 3.92 1st gear is so low,you’ll be well into 3rd before you hit 60. The 3.21 hits 60 right after shifting into 3rd.
- towing: for trailers at or under 8k, the 3.21 is fine. Yes it will operate one one gear lower pretty much the whole time, and be a little slower from a stop, but easily plenty of power.
- load capacity: no difference, so not a factor
I ordered and took delivery of the 3.92, and while it’s fine, had I ordered after having the 3.21, I probably would have gone 3.21. My travel trailer is around 6300#, and either works.
MPG wise, the 3.21 averaged almost 2 mpg better. I do 80/20 highway/city by miles, but 50/50 by time, and the 3.92 mileage is notably worse at stop&go and at speeds over 70. (should note the 3.92 truck was a couple hundred pounds heavier). The 3.92 turns 1980 RPM at 70, while the 3.21 does 1620. Excluding towing, I’m averaging 18 in the 3.92 etorque so far.
That all said, the 3.92 should be a tiny bit easier to sell, as it can do everything (except get better mileage). while some buyers will avoid 3.21 trucks.
Also, the 3.21 truck downshifts from 8th much more readily, and seems to come out of ECO more readily. (working on another info post, on reverse engineering the criteria for entering/exiting ECO).
Side note, I like the eTorque, and am not bothered by ECO or Stop-Start. I would definitely buy etorque again.
Anyhow, I quite like my truck so far, and am not trading it for a 3.21, but figured I’d pass on these observations for those considering their options.
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