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Realistic MPG with a Dmax 6.6

This is a discussion on Realistic MPG with a Dmax 6.6 within the Duramax Forum forums, part of the General Discussion category; I'm considering a 06 2500 4X4 with the Dmax/Allison combo. What are some of you realisticly getting MPG wise with ...

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    Realistic MPG with a Dmax 6.6


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    I'm considering a 06 2500 4X4 with the Dmax/Allison combo. What are some of you realisticly getting MPG wise with these trucks empty? Thanks

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    2500 6.0 vortec
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    Re: Realistic MPG with a Dmax 6.6

    My buddy got 16 city and 20 highway with his.

    2500 6.0 vortec 6in skyjacker lift with keys on 16in eagle wrapped in good year kevlar 285, LPP LT's, gmpp cam, efi live tuning software, true dual flowmaster 40 series Circle D 2500-2800.

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    Just Bump It BC Rod and Custom's Avatar
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    Re: Realistic MPG with a Dmax 6.6

    Dad's truck - Edge Programmer set to level 2, cold air intake, Amsoil Filter System, 5 inch straight exhaust. 22mpg highway with 285/75/16 on stock wheels.


    To mod, or not to mod, there really is no question!

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    Re: Realistic MPG with a Dmax 6.6

    I see mid to high teens around town or cruising at 55-60 on country roads. I'll see high teens to really low 20's on the highway at 65ish. I get about 8-11mph pulling my 28' trailer.

    Mods: 4" straight pipe, factory intake opened up. Efi-Live on +85hp economy (I'm going to try my race tune on the next hwy trip to see if it's better). 4" cognito lift, 285 tires. Truck weighs 8400lbs.

    2006 Chevy 2500HD
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    Re: Realistic MPG with a Dmax 6.6

    my bone stock '02 4x4 ex cab gets 18 anyway you drive it empty. loaded pulling a car trailer gets 14.
    andy

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    Re: Realistic MPG with a Dmax 6.6

    An unrestricted exhaust setup will get your most initial bang for your buck as far as MPG goes.

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    Astute as fek. DarkCharisma's Avatar
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    Re: Realistic MPG with a Dmax 6.6

    I've averaged about 14MPG over the last two tanks. That's 20/80 highway and city driving, with 10-15 min. warm-ups each morning. In the summer, it was a little closer to 16. Part of that drop is probably attributed mostly to warm up times and winter blend fuel, but I did go from a 275/55R20 to a 305/55R20, which is much wider and probably a little heavier.

    When I drive strictly highway and set the cruise at 75MPH, I have repeatedly been able to achieve between 17-20 MPG on the same trip, wind conditions permitting.
    Last edited by DarkCharisma; 11-10-2011 at 03:39 PM.

    Mine: '04 CTS-V | Poly Everywhere | LS7 clutch | Square 245/45R18 General AS-03's
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    Quote Originally Posted by randeez View Post
    he's got real problems, you think choosing which leather to rewrap in interior is easy?

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    Re: Realistic MPG with a Dmax 6.6

    Anyone getting in the 22-26 range?

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    Re: Realistic MPG with a Dmax 6.6

    Quote Originally Posted by Chingon HD View Post
    Anyone getting in the 22-26 range?
    22 can be done with the right tune, gears, tires, atmospheric conditions and proper driving conditions. Anybody getting over 22MPG regularly is either lying to you, or has every variable correct, and a very good right foot.

    Mine: '04 CTS-V | Poly Everywhere | LS7 clutch | Square 245/45R18 General AS-03's
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    Quote Originally Posted by randeez View Post
    he's got real problems, you think choosing which leather to rewrap in interior is easy?

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    Re: Realistic MPG with a Dmax 6.6

    My 06 RCLB got around 17 town and 23ish @70-75. That was with 265/75/16's, 3.73's mbrp exhaust, and a predator hand calculated. The dic claimed mid-high 20's all the time, if i puttered at 55-60 it would show mid 30's, but it was lying..
    Last edited by neubauej; 11-12-2011 at 09:00 AM.

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    Re: Realistic MPG with a Dmax 6.6

    The older trucks LB7 01-early 04 get the best fuel mileage, I usually get 17mpg in town driving like I stole it, and 22-23 highway thats with 33" tires and a 500 rwhp tune, I have a few buddies with LBZ's 06-07 stock your gonna get somewhere around 14mpg in town and 18-19 highway, if you go with a mild EFI tune or a mild handheld you should see 16-17mpg in town and close to 22mpg highway, it all depends on your foot!!!
    01 2500HD Duramax EFI TUNED
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    Re: Realistic MPG with a Dmax 6.6

    Quote Originally Posted by neubauej View Post
    My 06 RCLB got around 17 town and 23ish @70-75. That was with 265/75/16's, 3.73's mbrp exhaust, and a predator hand calculated. The dic claimed mid-high 20's all the time, if i puttered at 55-60 it would show mid 30's, but it was lying..

    The DIC always lies!!!
    01 2500HD Duramax EFI TUNED
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    the sea hates a coward rebelbowtie's Avatar
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    Re: Realistic MPG with a Dmax 6.6

    Quote Originally Posted by JustinSilverdo View Post
    The DIC always lies!!!
    No it doesn't, people just add aftermarket tires or change gear ratios and never calibrate the speedo. Even hand calculating can return false info. In both my 2004 2500HD amd my 2008 Audi A4 the DIC or MMI in the Audi consistently return accurate data. When compared to hand calculations they were around 1mpg +/- actual average.

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    Registered User JustinSilverdo's Avatar
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    Re: Realistic MPG with a Dmax 6.6

    Quote Originally Posted by rebelbowtie View Post
    No it doesn't, people just add aftermarket tires or change gear ratios and never calibrate the speedo. Even hand calculating can return false info. In both my 2004 2500HD amd my 2008 Audi A4 the DIC or MMI in the Audi consistently return accurate data. When compared to hand calculations they were around 1mpg +/- actual average.
    Even calibrating the tire size with EFI I have a couple 03-04 trucks tuned that are claiming 27+ mpg, you must be lucky with yours? Its a good reference but not accurate.
    01 2500HD Duramax EFI TUNED
    88 Chevy C1500 350 TBI 5 Speed Step-a-side soon to be 6.0 swapped
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    the sea hates a coward rebelbowtie's Avatar
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    Re: Realistic MPG with a Dmax 6.6

    27+ average or "instant" economy. I noticed the instant economy was always waaay off on my truck. But the MMI on the Audi is pretty advanced and displays AFR. That's the best tool for getting mpg's IMO.

    I am sure with EFI Live someone could get the DIC to display that info though.

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    Re: Realistic MPG with a Dmax 6.6

    Drove round-trip to my brother-in-law's motorcycle race today (Cow Dung Seasonal 2011, Expert/Unlimited Class--he won!) through a nasty cross-wind the way down. The way back was a lot nicer... fresh tank of diesel, averaged 13MPG on the way down and 19MPG on the way back, to give me an average somewhere around 16MPG.

    So, conditions hurt a lot. I didn't push past 70MPH with the wind and never above 75MPH once things cleared up.

    Just a little real-world report when things aren't always ideal...

    Mine: '04 CTS-V | Poly Everywhere | LS7 clutch | Square 245/45R18 General AS-03's
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    Quote Originally Posted by randeez View Post
    he's got real problems, you think choosing which leather to rewrap in interior is easy?

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    Re: Realistic MPG with a Dmax 6.6

    our 2001, 3500 gets 21, our 2005, 3500 gets around 16 but its a service truck, both of our 2006, 2500HD get around 19, our two 2011, 3500 get around 19 and about the same for our 2011 Denali HD

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    Astute as fek. DarkCharisma's Avatar
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    Re: Realistic MPG with a Dmax 6.6

    I've never heard the LML's getting over 16. People have HORRIBLE mileage claims over on duramaxforum.com with the '11 models. Is that hand-calculated, and are you averaging in Regen?

    Mine: '04 CTS-V | Poly Everywhere | LS7 clutch | Square 245/45R18 General AS-03's
    Hers: '02 Tahoe Limited | LM7 | G80 | GT4 | 265/75R16 BIG-O AT | Lots of leather and girly stuff

    Quote Originally Posted by randeez View Post
    he's got real problems, you think choosing which leather to rewrap in interior is easy?

  19. #19
    I Hate You All, Equally.
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    Re: Realistic MPG with a Dmax 6.6

    DPF kills the mileage. Most will see an average of 14MPG And not much higher than that even under ideal conditions.

    Funny to think that the process to clean up the exhaust, drops the MPG so significantly...which causes more em missions I would imagine. LOL


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    Re: Realistic MPG with a Dmax 6.6

    its just hand calculated but they dont get horrible mileage at all. they only have like 4000 miles on both of the duallys but the denali hd had 20000 and thats right around what you get hand calculated

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