Gear Ratios on the 1500

[Narg]

I went 3.21 in my truck. Love it. In your case, I believe 3.92 would be better. Though I would not recommend leveling. That causes problems zealots of the subject don't prefer to talk about.

 

[Marine Les]

My 2018 3.6 has 3.55s and I would rather have 3.92s. The 8spd. makes it work even with 3.55s.

 

[RLJ10X]

"Just fine" is not a standard unit of measure.

You can't argue math. The 3.92 has a greater mechanical advantage.

I'm not buying the 5 mpg loss going from 3.21s to 3.92. Sorry, I'm just not. Let's say you get +1.5, mpg with 3.21s, which even that is arguable. When you factor in the cost of a new truck,
depreciation, insurance, oil changes, transmission service, etc, difference in gas mileage between the 2 gear ratios is going to be a minuscule cost difference. Lower gears are so much more satisfying. Find another way to save a few pennies.

 

[Batt4Christ]

FYI as well, I get an INDICATED 22 mpg (of fuel, NOT gas) at 80 mph on the Interstate with a 3.92 Limited Slip rear differential! My 2015 Laramie has 17" wheels with 33" tires (Yes, off a Rebel, but I have the higher level of appointments) {Smaller wheels with larger sidewalls equals a MUCH better ride experience enhanced by the 4 corner air suspension} Oh, and it is a 4x4 as well.

The only thing I regret not holding out for is the RamBox!

IF I am loosing 10% in 8th gear, I don't mind. Yes, I KNOW it is an "instantaneous" reading, but I don't mind getting the MPH other vehicles are getting at 45 or 50 mph while doing 70 or 80 mph! (My wife's Lexus RX350 has an engine that is half a liter (The 350 means the engine in her car is a 3.5 liter engine) bigger than my 3.0L EcoD and she gets about half the mpg I get -- AND she says the ride in my RAM is better than in her luxury SUV!!!)

Absolutely no way you are actually getting that kind of mileage with 5.7 and the 3.92.

With my 3.92 equipped 2017, 22 was down hill at 70 mph on the computer.

At 80 on flat highway, 16-17 was as good as it got (indicated). Actaul calculated was always 1-1.5 mpg lower that truck’s computer.


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[tidefan1967]

Absolutely no way you are actually getting that kind of mileage with 5.7 and the 3.92.

With my 3.92 equipped 2017, 22 was down hill at 70 mph on the computer.

At 80 on flat highway, 16-17 was as good as it got (indicated). Actaul calculated was always 1-1.5 mpg lower that truck’s computer.


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He's got the Ecodiesel so if anything he could be doing better. If he drove the speed limit he could easily be pushing 26-27 and if he had the taller gears 30 MPG wouldn't be out of the realm of possibility.
Now I have 3.92s with the HEMI and 8 spd auto like you and I might get 17 at 80 on flat ground. I had a 3.21 truck previously and got 19 but it wasn't worth it to me. I hated it dropping down a gear going over hills and I live in an area with few hills.

 

[Ed F]

Nobody ever mentions off road crawling but I have to feel the 3.92’s are better when you need 1st gear low range.

 

[corneileous]

I’m just glad that ram gives us a choice. At least with the eight speed, it’s kind of like you can have your cake and eat it too with that high of a rear end because the eight speed will give you some of that back from what you would lose with that high of a gear and fewer transmission gears. And it works for the 392s as well because you get the luxury of the lowered gears when you need it, but you don’t have to feel it as much when you’re going down the highway. I’m still amazed that even at 70 miles an hour in my truck that even with my 392 rear end, I’m still only pulling 1500 to 1700 RPMs. Seems like if I remember correctly in my old truck, the 392 with that six speed was closer to two grand.


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[Elkman]

Nobody ever mentions off road crawling but I have to feel the 3.92’s are better when you need 1st gear low range.

Exactly! And having more gears in the transmission has nothing to do with the gain from a lower final gear ratio. The final gear ratio also determines towing capacity. With the V-6 engine having 3.55 gears provides a 1000 lb increase in towing capacity over a truck with the 3.21 gears.

For towing with a gas engine I have always bought vehicles with 4.10 gears as I can accelerate faster to merge safely with traffic at freeway onramps. I can pass tractor trailer doubles going up a grade in less time and this also is important if one travels in the mountains.

3.55 gears are available but a special option and not standard on the Ram 1500 trucks.

 

[pacofortacos]

I’m just glad that ram gives us a choice. At least with the eight speed, it’s kind of like you can have your cake and eat it too with that high of a rear end because the eight speed will give you some of that back from what you would lose with that high of a gear and fewer transmission gears. And it works for the 392s as well because you get the luxury of the lowered gears when you need it, but you don’t have to feel it as much when you’re going down the highway. I’m still amazed that even at 70 miles an hour in my truck that even with my 392 rear end, I’m still only pulling 1500 to 1700 RPMs. Seems like if I remember correctly in my old truck, the 392 with that six speed was closer to two grand.


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Unless you have much taller tires than stock, you aren't pulling 1500-1700 rpms at 70 mph. It's more like 1900 @ 70 mph with 33" tall stock tires with 3.92 gears.
If you are down to 1500 rpms you might want to check your rear as that is close to 3.21 range @ 70 mph.

 

[pacofortacos]

My 2018 3.6 has 3.55s and I would rather have 3.92s. The 8spd. makes it work even with 3.55s.

Yeah, the 3.6 needs rpms to make power. Bit gutless on the low end to me.

 

[runamuck]

3.21 will give you maybe 2 mpg better on the highway. I have gotten up to 21.5 on mine with the 3.92's so plenty good for me. the 8 speed has a very low 1st gear so it wont be too bad for towing most things. use tow/haul.

 

[Marine Les]

Yeah, the 3.6 needs rpms to make power. Bit gutless on the low end to me.

My guess is you are under 40 (im 71) because I have never had a truck as quick off the line as my 3.6. If you drive the 5.7 you are spoiled for sure. I have driven the old Dodges with the mighty 440 and they would not be even close to the Hemi.

 

[scott lass 18]

did mine right a way but then warranty is gone on it ok ! also a diablo sport so runs great for years get 9 to 21 better mpg 11 to 20 if I drive like a little old man hehehe ! if u ever tow then u ll be glad u did ! had mine done at ring and pinon shop great guys do susper work on all 3 of my trucks over the years ! dealer said it was bad pinon nut broken and greats just like new inside ! dont trust dealers at all anymore ! glad all they did fix but still a tick hummmm oh well no codes yet !

 

[pacofortacos]

My guess is you are under 40 (im 71) because I have never had a truck as quick off the line as my 3.6. If you drive the 5.7 you are spoiled for sure. I have driven the old Dodges with the mighty 440 and they would not be even close to the Hemi.

Nope significantly older than 40 lol I wish I was 40.
I have had several 3.6's in Caravans/Town and country/Pacifica and while the 3.6 is decent once you get over 3000 rpms it is a pig under 2000 rpms.
Though I think the transmission and gearing of the truck is much better than the vans. On my vans it's like it just has no power until the downshift - once the rpms are north of 3500 rpms she really comes alive.
I wouldn't want to tow my 5000 lb. boat/trailer @ 70 mph with the 3.6 in a ram, I just don't think it would be a pleasant experience.

Personally I think the hemi is a pig under 2000 rpms, my 5.9 had much more grunt from idle to 2000 rpms.
Same as 3.6 though, get some rpms in the 5.7 and she comes alive.
My 383's and 440's had much more grunt than the 5.7 also when tuned correctly.
Mind you I am also comparing a 5.7 with 8 speed trans and 3.92 gears to the above also. But the above were also not dead stock, not much as far as parts but some very fine tuning was done on them.
The 5.7 is close to max power on 87 octane fuel in stock trim. Where the 5.9 in stock tune was very detuned, same with 383's and 440's.

 

[Marine Les]

Nope significantly older than 40 lol I wish I was 40.
I have had several 3.6's in Caravans/Town and country/Pacifica and while the 3.6 is decent once you get over 3000 rpms it is a pig under 2000 rpms.
Though I think the transmission and gearing of the truck is much better than the vans. On my vans it's like it just has no power until the downshift - once the rpms are north of 3500 rpms she really comes alive.
I wouldn't want to tow my 5000 lb. boat/trailer @ 70 mph with the 3.6 in a ram, I just don't think it would be a pleasant experience.

Personally I think the hemi is a pig under 2000 rpms, my 5.9 had much more grunt from idle to 2000 rpms.
Same as 3.6 though, get some rpms in the 5.7 and she comes alive.
My 383's and 440's had much more grunt than the 5.7 also when tuned correctly.
Mind you I am also comparing a 5.7 with 8 speed trans and 3.92 gears to the above also. But the above were also not dead stock, not much as far as parts but some very fine tuning was done on them.
The 5.7 is close to max power on 87 octane fuel in stock trim. Where the 5.9 in stock tune was very detuned, same with 383's and 440's.

The older B engines with high compression were very stout but i was thinking about the the detuned versions in the later 70s that drank gas but did not have the grunt. I pulled my 4000# boat home from 2500' to 8000' with 2 6% grades and 3.6 did it well. Not my first choice for towing as i have a 5'9 Cummins for that. The low gears with the 8spd. allow the 3.6 to punch well above its' 220 ci.

 

[pacofortacos]

I wholly agree completely with all of that.
The 3.6 is a good running engine, it just has to have the rpms to really work well. Above 3500 rpms and it is a little beast. The roar up in the high rpms sounds really good for 3.6 L lol.

Even the later B/RB motors really didn't run that bad (not as good as they should) if you knew how to tune them - you really had to play with the timing curve - detonation was the biggest limiting factor on 87 octane but if the timing curve, a bit hotter ignition, the right plugs and carb set up just right, they were tolerable.
Imagine one of them mated to the 8 speed trans w/3.92 gears and modern fuel injection

 

[Ramjob]

Had 3.21 in my 2011 Hemi it was my First Ram 1500, always wounded why it was such dog off the line? Now I know, my 2020 has 3.92 hole lee chit!

 

[Elkman]

3.21 will give you maybe 2 mpg better on the highway. I have gotten up to 21.5 on mine with the 3.92's so plenty good for me. the 8 speed has a very low 1st gear so it wont be too bad for towing most things. use tow/haul.

Or you can drop you speed 5 mph and get an even greater gain in fuel economy.

Check the EPA calcs which are generous as they use testing that is done indoors and so no air drag and where the primary differerence was with the engine. Combined for the 3.6L is 21 mpg, with the 5.7L with etorque it drops to 19 mpg, and with the 5.7L engine alone it drops even further to 17 mpg. The difference in yearly fuel cost is only $300 a year or less than $1 a day between the best and the worst.

Bottom line is get the lower gears if you want to go off road or tow and expect to pay an extra $1 a day for gas.

I have a SUV with a gas V-6 engine and if I hot rod it around town my MPG is in th 15-16 mpg range but if I drive it with care I can get 24-32 mpg depending on the terrain.

 

[runamuck]

ya I 'm happy with my '19 laramie..I got the hemi and 3.92 because I have a travel trailer and a utility trailer that I use often for runs to home depot and such. In october the wife and I did 3500 mile tour of the west..colorado/utah/wyoming and back and I got as high as 21.5 mpg..mostly 75-78 on the highway. hard to beat that for a truck..I get anywhere from 8 to 10.5 towing my 6000# travel trailer at 67-68 depending on the terrain. I have always used regular grade gas in my truck except in some areas when I cant get it. 5.7 and lower gears more desirable at trade time seems to me.