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Smells like Bananas
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7,242 Posts
Discussion Starter · #1 · (Edited)
I have been noticing that the people that get better MPG are running a 4" Exhaust. I want to know if this is true. I have the 5" TBE no Muffler. I get 14 MPG on average. 10.5 MPG with 8000lbs behind me and 8.4 MPG with 19,000lbs behind me.

If yall can, Copy and paste this below and fill it in. Please only hand Calculated!!!

Year Model:
Truck Model: (QC short bed, QC, Long Bed, C&C, or Mega Cab)
Drive: (2wd or 4wd)
Trans:
Lift:
Tires and Rims:
Speedo Corrected:
Miles to a Tank with 30gal fill up:
Highway speeds:
City MPG:
Highway MPG:
City Towing:
HW Towing:
DPF:
TBE or Down Pipe Back:
Muffler or not:
Exhaust Size:
EGR Blocked:
Programmers, What level:
Intake:
Flash:
Final Drive Gear:

Heres mine
Year Model: 2007
Truck Model: Mega
Drive: 4wd
Lift: 2" Leveling
Tires and Rims: 20x10 Rockstars, 33x12.5x20r Nitto Terra, (A/T's)
Speedo Corrected: Yes
Miles to a Tank with 30gal fill up: around 390 to 410
Highway Speeds: 75 to 85
Trans: Auto
City MPG: 13.6
Highway MPG: 14.5
City Towing: 7-10ish
HW Towing: 8-10.5ish
DPF: 5"
TBE or Down Pipe Back: TBE
Muffler or not:No
Exhaust Size: 5"
EGR Blocked: No
Programmers, What level: PMT(verys), MP8(Usually on 100%)
Intake: Mega Cannon
Flash: AX
Final Drive Gear: 3.73


I am hoping yall will do this because i want those that are getting great MPG's, I want to see what is so different from us who are getting crappy MPG's

Also if you can, give us a brief description of you driving habits.

Like i can be pretty hard on my truck at times. If i have the programmer turned up i like to see smoke, If its turned down i drive like a blind grandpa, slow.

The reason for this is that not everybody has there SIG filled out or they leave some of the info out. Be a friend and help out and fill this out. It could help us get a little better MPG.

If there is some info that yall want to see added let me know and i can add it to the list to fill out
 

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1,157 Posts
Year Model: 2007.5
Truck Model: QC, LWB
Drive: 4wd
Trans: G56
Lift: none
Tires and Rims: Stockers
Highway speeds: 70 mph
City MPG: varies - as low as 13-14
Highway MPG: 16.5-17.9
DPF, Exhaust Size: stock
TBE or Not: no
EGR Blocked: no
Programmers, What level: no
Intake: stock

Mine is stock, but I'm seeing better than you are. I run probably 90% highway. My MPG started at 14.5 and went up to where it is now at 27k miles.

I know it isnt exactly what you're asking for, but I've also seen the stock trucks vary greatly so I'm thinking that might be part of what you are seeing.

Regens keep me out of the 18-19's now. My overhead has seen as high as 21-22 but drops like a rock during regen. So I'm going to estimate I'll see 18-20 MPG once I get rid of the DPF.
 

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1,157 Posts
Might want to add flash level too, I'm at AX.

Did you correct your numbers for your tire size difference?
 

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692 Posts
Year Model:2007
Truck Model: (QC short bed, QC, Long Bed, C&C, or Mega Cab) qc long
Drive: (2wd or 4wd) 4x4
Trans:auto
Lift: stock
Tires and Rims: stock... 6 of them
Highway speeds:75-85
City MPG:14.6
Highway MPG: 18.9 and 20 with camper shell
City Towing: 11
HW Towing: 9000 -15, 12000-14, 24000 - 10.6
DPF, Exhaust Size:5" with magnaflow muffler
TBE or Not:yes
EGR Blocked:no
Programmers, What level:edge level1,mp8 80%
Intake:s&b
ax flash
tires at 70psi
I take of slow and build up speed slow and stay just above momentum until I reach speed and find that helps whenever I have to increase speed.
 

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Smells like Bananas
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7,242 Posts
Discussion Starter · #6 · (Edited)
Might want to add flash level too, I'm at AX.

Did you correct your numbers for your tire size difference?
Thanks, i added that can a couple more

Derekj, thats how i pull, not how i drive unloaded though
 

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Washington Chapter Vice President
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5,055 Posts
Year Model:07.5
Truck Model: (QC short bed, QC, Long Bed, C&C, or Mega Cab) QCLB
Drive: (2wd or 4wd)4wd
Trans:Manual w/ Dual Disk (has dropped me about .5)
Lift:Stock
Tires and Rims:Stock
Speedo Corrected:yup
Miles to a Tank with 30gal fill up:435 to 520
Highway speeds:65-75
City MPG:17
Highway MPG:no highway trips yet
City Towing:~13
HW Towing:15
DPF, Exhaust Size:No DPF 4" to the stacks
TBE or Not: No
EGR Blocked:Yes
Programmers, What level:Edge 6, MP-8 100%
Intake:aFe Pro Dry
Flash:G30 done, av? Dont know for sure. Not AX though.

I have been driving hard lately. Last tank was only about 15 MPG. When i take it easy its easily 17 MPG. I have about a 600 Mi round trip planned at the end of the month i will report on that.
 

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Premium Member
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1,958 Posts
Year Model:03 2500
Truck Model: (QC short bed,
Drive: ( 4wd)
Trans:6 speed
Lift:na
Tires and Rims:stock steel wheel stock size bfg rugged trail tas
Speedo Corrected:yes
Miles to a Tank with 30gal fill up:450-550 on 28 gal depending
Highway speeds:65-70
City MPG:16.5 stock 17.5 with smarty and 19.5 when i drove decent
Highway MPG: about 20-22
City Towing:not sure about same
HW Towing:not sure about 17 tho
DPF, Exhaust Size:3.5 down pipe 4inch after that no cat or muffler
TBE or Not:
EGR Blocked:
Programmers, What level:smarty level 5
Intake:na
Flash:na

driving like an idiot i got 16.5 stock with the smarty on level 9 i got 15.5 put it to level 5 drove nice and got 19.5 drove like an idiot again and have been getting 17 ish ever since. all in town hope that helps.

ps that with a very full 28 inch deep tool box and a ladder and me
 

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Premium Member
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1,958 Posts
sorry its not a 6.7 but wanted to post it anyways maybe it will help
 

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90 Posts
I was told by my tech that the 5" systems are actually loosing in the area of 25+ HP ... that's gota equat to loss in fuel economy somehow
 

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155 Posts
Year Model: 2007
Truck Model: (QC short bed, QC, Long Bed, C&C, or Mega Cab) short bed
Drive: (2wd or 4wd) 4wd
Trans:dunno
Lift:no
Tires and Rims: stock
Speedo Corrected:n/a
Miles to a Tank with 30gal fill up: 600 +/-
Highway speeds: 55-75
City MPG: 15.1
Highway MPG: 20.5
City Towing:n/a
HW Towing:n/a
DPF, Exhaust Size: 5" TBE w/ Muffler
TBE or Not:yes
EGR Blocked:no
Programmers, What level: Edge Levek 1
Intake:no
Flash:ax
 

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Registered
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634 Posts
Year Model:07.5
Truck Model: (QC short bed, QC, Long Bed, C&C, or Mega Cab)QCSB
Drive: (2wd or 4wd)4wd
Trans:g56
Lift:2in leveling blocks
Tires and Rims:285/70r17 terra grapplers/ stockers
Speedo Corrected:yes
Miles to a Tank with 30gal fill up:just did a trip to portland and back 578miles 31.2 gallon
Highway speeds:70 through mountains 75 on flats
City MPG:around 13 in winter 14.5 in summer
Highway MPG: 17 to 19 average 21.9 best
City Towing:none really
HW Towing:9k lb camper 11 to 12.7(best)
DPF, Exhaust Size:stock
TBE or Not:stock
EGR Blocked:no, not yet
Programmers, What level:stock
Intake:stock
Flash:latest and greatest

I do notice when my speed gets over 70 according to the overhead the mileage drop dramatically. I wish they would have had the 3.42's for an option when I bought mine. I think it would help a lot. I have the 3.73's now. I do use cruise as much as possible, but I'm not afraid to mash on it either. I usually drive pretty easy, not like a blind grandpa, but not always like a maniac either. I do hot rod when somebody wants to play, or when I feel like playing. The city mileage with this one is lower than my '00 but the highway mileage is pretty close. Maybe only about 1mpg lower.
 

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Smells like Bananas
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7,242 Posts
Discussion Starter · #13 ·
What i have been thinking for a while now is i Really believe that we need some type of back pressure on a 6.7. My concern here is to look at your exhaust configure and your reported MPG's. For the most part everybody has one or two things the same and everybody have one or two things different. I think the 5" TBE is great but it may just need to be ran with the Muffler to get the benefit from it. But i think i might just pull my muffler delete and put a "made washer" that will choke it down to a 4" ID in it.
 

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331 Posts
Year Model: 07.5
Truck Model: (Mega Cab)
Drive: (4wd)
Trans: G56
Lift: no
Tires and Rims: stock
Speedo Corrected: n/a
Miles to a Tank with 30gal fill up:500 +/-
Highway speeds: 80 mph
City MPG: 15.5
Highway MPG: 19.5
City Towing: no towing yet
HW Towing: no towing yet
DPF, Exhaust Size: 5"
TBE or Not: yes
EGR Blocked: yes
Programmers, What level: Edge to 0, MP-8 at 75%
Intake: AFE PG7
Flash:AX

I dont know if the back pressure thing is valid with these turbo's we have on the 6.7's. I have heard they dont need it. I have also only filled up 2 times since the TBE. I am hot rodding the piss out of her cause i love the sound I drive about 60/40 highway to city miles on a tank. I am getting right around 17 mpg per tank right now. Like I said I am always on the throttle though. I can see it at 20 if I take it easy I think. I would also take a lot of these with a grain of salt cause a lot of people take the overhead as actual. I have seen 23 on my overhead and it stays between 21-22 mpg at all times. So you guys that are not actually hand calcing it at fill up please dont post.:thumbsup
 

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Smells like Bananas
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7,242 Posts
Discussion Starter · #15 ·
So you guys that are not actually hand calcing it at fill up please dont post.:thumbsup
no over head readings,
do you have the muffler on?

also if any of yall can add if you think you have bad turbo lag or not. I do, it sucks
 

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209 Posts
Year Model: 07.5
Truck Model: regcab long bed
Drive: (4wd)
Trans: G56
Lift: no
Tires and Rims: stock
Speedo Corrected: n/a
Miles to a Tank with 30gal fill up:450-500
Highway speeds: 75+
City MPG: 15-17
Highway MPG: 20-21.7
City Towing: stock 8, after 15
HW Towing: none
DPF, Exhaust Size: 4
TBE or Not: yes
EGR Blocked: yes
Programmers, What level: PMT extreme mp-8 100% above 70mph, PMT tow mp8 100% below 70
Intake: stock minus baffle
Flash:G30
I do have turbo lag if i take off easy, but if i hammer it my boost will jump to 35-36 in a heart beat.


5in does hurt u under a certan horse power, and turbo diesel do not need back pressure the turbo is plenty.
 

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Smells like Bananas
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7,242 Posts
Discussion Starter · #17 ·
well yal that have the 4" or 5" with muffler seem to be getting better MPG. I am just trying to get enough people to fill this out to see what the difference is. So far that is the only major factor that i see other then the EGR.
 

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388 Posts
Year Model: 08
Truck Model: quad cab short bed
Drive: (4wd)
Trans: auto
Lift: no
Tires and Rims: stock
Speedo Corrected: n/a
Miles to a Tank with 30gal fill up: 637-672 last two fill ups
Highway speeds: 75-85
City MPG: 18-19 driving the speed limit (40mpg)
Highway MPG: 21-22
City Towing: 15
HW Towing: about 16 depending on wind
DPF, Exhaust Size: 5
TBE or Not: yes
EGR Blocked: yes
Programmers, What level: edge wit att level 5 on highway 3 in city mp8 on 75-80%
Intake: air raid
Flash:G30

most of mine was highway the past week. i filled up with lsd diesel and got 723mile on a tank.

then i put bio diesel in and ran b100 and lost alot of power and got 452 on that tank.
 

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707 Posts
Year Model: 2007
Truck Model: (QC short bed, QC, Long Bed, C&C, or Mega Cab): QC Short
Drive: (2wd or 4wd): 4wd
Trans: 68RE
Lift: 2" level
Tires and Rims: 35x12.5 stock wheels
Speedo Corrected: YES
Miles to a Tank with 30gal fill up: about 330-350
Highway speeds: 70
City MPG: 11-12
Highway MPG: 16-17
City Towing: none
HW Towing: 11mpg
DPF: Stock
TBE or Down Pipe Back: Stock
Muffler or not: Stock
Exhaust Size: 6.7
EGR Blocked: NO
Programmers, What level: None
Intake: Stock
Flash: AX (just got it done, no mpg report yet)
 

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340 Posts
You should also post your gear ratio. I have the 3.73 and my friend has 4.11 or something and i get alot better milage. I would say that the best thing to do to increase milage would be to instal front hubs on the 4X4 trucks. Spinning all of that stuff up front is said to account for 1-2 MPG.
 
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