Rebel Fuel Economy and changing to the 3.21 Rear End

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Dennis Ferdig

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Does anyone know if changing just the 3.93 rear end back to the 3.21 on my Rebel would provide the same fuel economy as the standard 1500? I rented a Big Horn Edition a few times and got over 20 MPG traveling with plenty of power to spare. I get between 12.7 and 15.5 MPG with my Rebel. All other motor and gearing seem to be identical, its just the rear end gears.
 

crash68

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You would have to change the front differential also, do they even make a 2wd Rebel?
The type of tires on your Rebel vs what's on the BigHorn will also contribute to lower fuel economy. The tread pattern of all terrain type tires doesn't roll as efficiently. Also if you Rebel tires have a higher load rating, they are most likely a heavier tire which also contributes to the lower fuel economy.
 

canadiankodiak700

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If only you were closer, i would swap my 3.21 front and rear gears for yours.
3.21 are great for fuel economy, but with my 3.6 pulling my cargo trailer i would benifit with 3.55 or really anything

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crash68

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The Rebel isn't as aerodynamic as the Big Horn either.
I forgot about this^^^
The Rebel doesn't have the AGS like the BigHorn and the air suspension doesn't drop as low while in AeroMode.
 

ramffml

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The rebel is also lifted (more drag), has beefier tires (more resistance/weight), has skid plates (more weight) etc. You won't reach bighorn levels of mpg but some good street tires might gain you 1 to 2 mpg alone.
 

corneileous

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My question to the OP… and I know you bought pretty much an off-road ready truck but do you actually go off-road at all? If you do, do you actually go places where you have to have such a heavy duty 10 ply tire to get there? If not, I would probably worry about ditching those heavy duty tires before I did anything because that’s probably where a lot of your fuel mileage is going.

The Rebel is a great concept but damn, I think they really screwed up by putting those heavy duty 10 ply tires on there assuming that anybody who buys one that does have plans to go off road is gonna always go places where you need that heavy of a tire.


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olyelr

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The rebel is also lifted (more drag), has beefier tires (more resistance/weight), has skid plates (more weight) etc. You won't reach bighorn levels of mpg but some good street tires might gain you 1 to 2 mpg alone.


^^^^^^this.

I have a big horn for a work truck, and i checked every single tank of gas for the first few years. Was always 16-18 in the winter, and 18-20 in the summer. As soon as i put new tires on it (stock size goodyear ultraterrain, which are still not a lt/heavy tire) the truck easily lost a solid mile per gallon. With the rebel being lifted an inch or more, combined with being heavier...its just not gonna be as fuel efficient.
 

scubaseth

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Anyone have mpg on the ecodiesel Rebel? It looks like all the rebels have higher towing with the lower gears. The offroad capability would be great over my 1500.

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ramffml

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Anyone have mpg on the ecodiesel Rebel? It looks like all the rebels have higher towing with the lower gears. The offroad capability would be great over my 1500.

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You cannot look at simply one limit (tow spec) and think you can a trailer at that limit. The vast majority (like 90% + ) are limited by payload. And Ram with a diesel, especially Rebel trim, is going to be limited to 8000 pounds or less. They're just too heavy with the combination of diesel, skid plates, offroad tires, 4x4 etc etc.
 

scubaseth

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You cannot look at simply one limit (tow spec) and think you can a trailer at that limit. The vast majority (like 90% + ) are limited by payload. And Ram with a diesel, especially Rebel trim, is going to be limited to 8000 pounds or less. They're just too heavy with the combination of diesel, skid plates, offroad tires, 4x4 etc etc.
Agreed. I already tow below those limits with my ecodiesel 1500. It looks like most 2021 rebels come with the 3.9 gears. I understand they are heavier. That's why I was curious if mpg is what is advertised for the rebel diesel or way less.

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