how bad does the 3.92 gearing affect MPG?

[spelunk68]

Building out a Ram I want to order and was wondering how going with the 3.92 gearing would affect milage. I am not hugely concerned about loosing a mile or so off of the MPG but do not want to wind up with a 10 MPG gas hog. I have looked around and can not find any specific info on it with the 5th gen. I do tow but nothing major, just a 12 foot dual axle cargo box. Also does the 3.92 ration make the truck have more pep off the line? I understand a loaded 4x4 5.7 e-torq is not a 22 MPG truck but I also do not want to make a huge mistake that I regret. This is in reference to the 1500 series.

 

[Trouble1233]

My wife drives my truck and she’s not babying the truck but around town she gets 16-19 on highway


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[Luxy72462]

There’s other threads on here about this. Difference is maybe 1 mpg.


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[Trouble1233]

I also have etorque system..love it


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[spelunk68]

Thanks, that is what I was looking for

 

[camaro430sut]

I just averaged 18.6 in my e-torque crew cab 6'4 bed with 3.92s on an 800 mile rou d trip. Loaded with about 800-900 pounds in the bed

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[bazbob]

If you plan on using your truck to tow, get a 3.92 and don't worry about the MPG. If you are not towing or seldom tow, then you might as well get the 3.21

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[SD Rebel]

Going from the widest range possible, the E-torque 3.21 vs Non E-torque 3.92 is probably around 2-4 mpg in he real world, range widens even more if you do more city driving.

This is not including ORP/33" tired trucks, which lowers it another 2 mpg or so.

 

[kapinallinen2]

3.92 at 90 mph on I-95, yeah, about 10 mpg with Rebel and roof top tent...

 

[iLikeTurtles]

My 3.21s non etorque net me around 14.5mpg.

Issue is, do you drive mostly highway or city? I drive so much city/non highway (even though 50%+ is highway, still isnt enough) that 3.92s would probably net me better fuel mileage around town.

I would get 3.92s unless i did 80%+ highway. Even then, i would probably rather have the extra pep down low and go for 3.92s.

 

[HemiDude]

Totally empty I have averaged 22.5 mpg over a long trip, 5.7 crew non-e w/4wd and 3.92. Loaded 10' trailer 19+. 3.92 definitely gives more pep from a start regardless of empty or towing.

 

[WXman]

3.92 all day with the gas engine. You'll actually see better mileage around town and performance is also better.

 

[Willwork4truck]

If you plan on using your truck to tow, get a 3.92 and don't worry about the MPG. If you are not towing or seldom tow, then you might as well get the 3.21

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If I were towing that amount on a fairly regular basis, I’d go with 3.92 ET. If its only occasional towing under 8K I’d go 3.21 ET.

 

[Trippi]

3.92 at 90 mph on I-95, yeah, about 10 mpg with Rebel and roof top tent...

Smiles per Gallon

 

[kapinallinen2]

Smiles per Gallon

Yes sir,(kyllä) to the point that my cheeks hurt!

 

[jkm312]

Not mentioned yet is I have found less downshifting on the highway to maintain cruising speed with my 3.92. Along with that in town you will notice the MDO stays on a little more. Real world mileage is a tough one to anticipate. Some here get above 20 mpg highway with a 3.92. I never have, 19.5 is the best I've gotten out of mine. I'm about 2100 to 2250 RPM's on the highway to move with traffic. Lots of varying factors, road conditions, flat land, hills, wind, gasoline type, exhaust, air breather, driving style, weight of truck and cargo. You will slog along with some low mileage until you break about 10,000 miles on the clock or so.

I stayed out of the e-torq option. For me, I don't think I'm missing anything I'm interested in. Owned the truck for 18 months.

If you are going to lift the truck and go bigger wheels and tires, then 3.92 is the way to go for you. I have 20" tires and it is rock solid acceleration for truck. Put your foot in it and it will put you back in the seat.

For me, I ordered the 3.92. I would do it again. I like the torque on the bottom end. I tow a little but nothing to get excited about or anywhere near the limits of the truck.

 

[AtlasRam1500]

I have two 19 a Laramie and Limited both 4x4 Laramie 3.21 .Limited 3.92 both 5.7 hemi
Laramie 3.21 i avg 17 city 20.5 hwy
Limited 3.92 Avg 14 city and 18 hwy

If i had to choose again i go with the 3.21 keep in mind i do not pull a trailer or boat . both truck are stock except the Limited has the Rambox.

My Limited is at the dealer getting a leveled and 285/55/22 Installed so i know my MPG will go down.

Hope this help

 

[notilloc]

I average 13-14 in town, 15-19 on the highway. I have 3.92 and the off-road package, I think the more aggressive tires might be why I get such terrible mileage. I don't drive very hard, but I always get terrible mileage. My friend has the same truck as me just without the off road package and gets 3-4mpg better than me on the highway, it's frustrating!

 

[SD Rebel]

I average 13-14 in town, 15-19 on the highway. I have 3.92 and the off-road package, I think the more aggressive tires might be why I get such terrible mileage. I don't drive very hard, but I always get terrible mileage. My friend has the same truck as me just without the off road package and gets 3-4mpg better than me on the highway, it's frustrating!

Yup, even street tires that are only slightly larger will yield negative mpg. Just going half an inch higher on street Michelins netted a 1 mpg loss on a previous truck.

Imagine A/Ts and in the larger traditional sizes, makes a huge difference, larger than axle ratio by itself.

 

[iLikeTurtles]

I have two 19 a Laramie and Limited both 4x4 Laramie 3.21 .Limited 3.92 both 5.7 hemi
Laramie 3.21 i avg 17 city 20.5 hwy
Limited 3.92 Avg 14 city and 18 hwy

If i had to choose again i go with the 3.21 keep in mind i do not pull a trailer or boat . both truck are stock except the Limited has the Rambox.

My Limited is at the dealer getting a leveled and 285/55/22 Installed so i know my MPG will go down.

Hope this help

Would love to see pictures after install.