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Discussion Starter #1 (Edited)
This may have been discussed before but. . .

In reading some other posts on MPG, it looks like the 4.11 rear gets better mileage than the 3.73 with the Auto Trans. Is this true?

I experienced this between a 2000 and an 01. My partner had a 2000 and I had an 2001. His was a 4.11 and mine was the stock rear of 3.?? (What ever it was) I couldn't do any better than 20 MPG while he got 24!

What are you guys getting with the different rears in the 07.5 and 08's? I can't do any better than 14 with 3.73's and I don't beat it. I get 13.5 with the trailer
 

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you might get more response in another forum
 
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Discussion Starter #3
Yeah I'm waitin for a moderator to move this. I don't know the lay of the land yet

Thanks
 

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Si vis pacem, para bellum
2008 Ram 2500 QCSB, 2020 Jeep Wrangler JLUR
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I can't offer much information that will correspond to your own vehicle but I have 3.42 gears, 35" tires, and a G56 manual transmission and I am getting 17mpg on the highway (unloaded) with a little city driving mixed in. i like the fact that at 62mph I am at around 1600rpm.
 
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Discussion Starter #7
Between 14 and 14.5 with my 3.73's in a megacab dually. Seems to be getting better everyday. Could be the warmer weather??? I'll take your 13.5 pulling though. Just traded my 06 McKenzie Starwood Travel Trailer for 09 Keystone Sprinter 311bhs. Overhead averaged about 8.5 in the 180 mile round trip to the rv dealer and back. It is what it is though. My hemi had been down in the 6 mpg range pulling that same 06 starwood, and this 6.7 pulls hands down better than that did. I also don't baby anything. I get kind of a kick out of going around dmax's and stroker's. Can't help myself.
 
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shoot, beat me to it!:lol3:
:confused:

Oh That's OK. . . I was a Duh. There's so many forums to choose from. Hey! I was CLOSE! I'm the one who reported it. I just don't know my way around completely yet. As a forum owner, I know what has to be done. . . Thanks guys.
:thanks:
 
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I can't offer much information that will correspond to your own vehicle but I have 3.42 gears, 35" tires, and a G56 manual transmission and I am getting 17mpg on the highway (unloaded) with a little city driving mixed in. i like the fact that at 62mph I am at around 1600rpm.
See That's what I heard back in 2000 too. The manuals did good with the 373 and the autos did good with the 411's. You would think those nits up in Michigan would explore that.

I still don't have enough to go by though. This may be a solution to the crappy mileage. It must have something to do with the way the trans loads the engine at different speeds. If I am going to spend money on this truck, I want to spend it in the right place. No sense buying stuff that isn't doing anything.

Let's face it. 3 MPG for a gear change is significant! That's 36 Bucks a tank saved.
 

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I would have to agree with the above statement on the 4.11 gears better in the auto tranny. I am running the 68rfe and I get the same mileage in 5th as I do in 6th when towing. I swear mine just acts like its beggin' for the 4.11's LOL

My best fuel mileage on the highway while just the truck running by itself has been in the high 16's and the best towing mileage on my route has been 13, but that was a one time treat. Most of the time towing I get from 10-12. All these numbers since I have the Juice w/Attitude, EGR delete, DPF delete and the AX flash...

When I first got my 07' I got 7-8 towing and it was my first Dodge and I almost passed out LOL... My old 95 stroker gets 12 pulling the same GN trailer. I am slowly getting my 6.7 all built like it should be and how I have to have it or it will break me pulling the miles I do every week...
 

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I put 3.37 in my new truck at 2000 miles. after spending $2400 buks my tac dropped from 2100 rpm to 1600 at 70. i went from 12 mpg to 13. wowww. how long with it tak me to get my money back? Now I'm going to delet dpf, egr, should ( hopefully ) i'll get a pretty good jump.
 

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I have a stock 2007.5 - 3500 Mega Cab, with 3:73's.
I only have 5000 miles on her, but have always hit 18 mpg on highway trips.
I hope to see that increase as the engine becomes broke in, and I can then switch to a better grade motor oil.
 
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I have a stock 2007.5 - 3500 Mega Cab, with 3:73's.
I only have 5000 miles on her, but have always hit 18 mpg on highway trips.
I hope to see that increase as the engine becomes broke in, and I can then switch to a better grade motor oil.
How fast are you driving?

We seem to be all over the place with the MPG
 

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Si vis pacem, para bellum
2008 Ram 2500 QCSB, 2020 Jeep Wrangler JLUR
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Also are you going by the overhead or hand calculating? That needs to be a constant for any of these measurements to be statistically correlated. I drove 250 miles this morning and my overhead said 18.6 when I got home, but was in actuality 17.6 hand calculated. Overheads have been known to be .5mpg off from hand calculated one fillup and 3mpg off the next fillup on the same truck. They are NOT an accurate method of estimating fuel economy.
 

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I have a stock 2007.5 - 3500 Mega Cab, with 3:73's.
I only have 5000 miles on her, but have always hit 18 mpg on highway trips.
I hope to see that increase as the engine becomes broke in, and I can then switch to a better grade motor oil.
I have 8,000 miles and I can have got 19.3 on highway trips easily.
 
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Discussion Starter #16
Mine appears to be constantly 1 MPG off. Even on 1000 mile trips
 

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DieselPig,

Now you said you went from 2100 to 1600 rpm's and your signature shows you have the 6 speed tranny and that you had the 4.10's and went to the 3.73's, is this the manual tranny or the auto dude???

Did you have your dealer do all this work for you and get the gears or what? Do you happen to know what the break down of the costs were. like the price of the gears and how much labor was? If you don't mind sharing. I sure know I have been wanting to go from 3.73 to 4.10 in my auto 6 speed. You should get your mileage working much better for you once you get the DPF and EGR off, along with something like the MP8... Darn shame we have to spend so much more money to get these trucks running and getting better fuel mileage...

Guys, to get this all posted where we all can use this info, just post how many miles you drove and how many gallons you put in. Then to know what tranny your running(auto or manual) and type of driving and speed for the most part or average. This info along with the rearend gear your running would help us all know maybe more about what going on...
 
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