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  1. #1

    duramax mileage improvement?

    I have a 2003 duramax 4 door dually and I tow a trailer long distances on occasion. I need to pull the best fuel mileage out of this thing I can, hence the reason I went to a diesel. So far just has a volant cold air intake. Going to a straight 4" exhaust. What else can I do reasonably? Is there a decent tuner (or tune) I can run on the truck to help? Any other ideas?
    2012 Street Glide
    1971 Vista Cruiser 455
    2003 Duramax Dually Silverado 4x4
    1986 442

  2. #2
    Bob the Builder says: 88Nightmare's Avatar
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    A tuner really helped my truck. Also, with this colder weather, you may want to get a grill cover, aka "winter front". I pick mine up tomorrow.

    Synthetic fluids in the axles and t case could help too. Make sure tires are aired up correctly.
    Quote Originally Posted by pOrk View Post
    All democrats like to work on wood, zing!
    The democracy will cease to exist when you take from those willing to work and give to those that are not - Thomas Jefferson
    2008 Yamaha FZ6
    2005 Silverado 2500HD 4x4 duramax

  3. #3
    A regular know-it-all Tetris Champion Snake Champion Lasagna From Heaven Champion Mac Man Champion Mahjong. Champion Mini Putt 3 Champion Plastic Saucer Champion Ratman Ralph Champion Prince Valiant's Avatar
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    Make sure you perform the driver mods too...
    1979 Lil' Red Express -Officially the quickest "bolt-on" LRT in the country.
    1989 Shelby CSX #500/500
    The most powerful production Minivan, ever...

    Be sure to check out my weekly adventures on the second page of your Sunday Comics!

  4. #4
    A few less pounds in the midsection? Maybe a lighter foot? Watch the top speed? All easier said than done! lol

    Quote Originally Posted by Prince Valiant View Post
    Make sure you perform the driver mods too...
    2012 Street Glide
    1971 Vista Cruiser 455
    2003 Duramax Dually Silverado 4x4
    1986 442

  5. #5
    I actually got a grill cover with the truck so that works. I always watch tire pressure, I cant afford to replace 6 tires all the time! Fluids couldnt hurt either. What kind of tuner I guess is more my question than if I should...Am also doing injectors soon, that will hopefully help more than hurt.

    Quote Originally Posted by 88Nightmare View Post
    A tuner really helped my truck. Also, with this colder weather, you may want to get a grill cover, aka "winter front". I pick mine up tomorrow.

    Synthetic fluids in the axles and t case could help too. Make sure tires are aired up correctly.
    2012 Street Glide
    1971 Vista Cruiser 455
    2003 Duramax Dually Silverado 4x4
    1986 442

  6. #6
    Flyin SS fly5150's Avatar
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    I have an edge tuner I took out of my truck, works great, and mileage increase. LEt me know if your interested.
    -Dave
    03 Audi RS6 -v8 twin turbo-
    02 Crewcab Dually -dropped and smoking on semi wheels -
    02 VW Jetta -1.8t will nevar lose-

  7. #7
    The syn. fluids in the diff. trans. and motor are a big help with the cold weather, and a lite foot also helps.

  8. #8
    have pot, will stir WickedSix's Avatar
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    Custom tunes will provide the most benefit and are comparable in price to the good tuners out there. Nick @ Duramaxtuner across the border in Il is one of the better ones around..... avoid Dan's diesel performance tuning at all costs...he will nuke ur trans.

    That said, best milage improvement is a light and steady right foot

  9. #9
    Bob the Builder says: 88Nightmare's Avatar
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    I have a bully dog gt, purchased from axis racing (flicktitty and Lizmo) and it's great. I've heard bad things from duramaxtuner on the national dmax boards. The thing I like about the bully dog is the monitoring device, and it's safe. I'm not looking to replace my trans under emergency conditions so keeping it safe was key for me.

    There's many other tuners across the country that can make a tune file for you with efi live... Just need a way to load it into your PCM. Pm me, I can give you all sorts of info on that
    Quote Originally Posted by pOrk View Post
    All democrats like to work on wood, zing!
    The democracy will cease to exist when you take from those willing to work and give to those that are not - Thomas Jefferson
    2008 Yamaha FZ6
    2005 Silverado 2500HD 4x4 duramax

  10. #10
    Bob the Builder says: 88Nightmare's Avatar
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    Quote Originally Posted by Old Guy View Post
    The syn. fluids in the diff. trans. and motor are a big help with the cold weather, and a lite foot also helps.
    There's strong mixed reviews on running synthetic in the Allison trans... Everyone says best bet is to just stick with the dex 3
    Quote Originally Posted by pOrk View Post
    All democrats like to work on wood, zing!
    The democracy will cease to exist when you take from those willing to work and give to those that are not - Thomas Jefferson
    2008 Yamaha FZ6
    2005 Silverado 2500HD 4x4 duramax

  11. #11
    Quote Originally Posted by 88Nightmare View Post
    There's strong mixed reviews on running synthetic in the Allison trans... Everyone says best bet is to just stick with the dex 3
    Most things now are coming with synthetic, both for the improvement in MPG and life of the equipment it is put in. One other thing with synthetics is the extended drains of the oils. I run Schaeffers 7000 5w-30 with a extended drain of 10,000 miles. First truck had 321,000 miles before I made it my weekend bracket racer. Second was a s-10 with 287,613 miles and was traded for a newer s-10 and now has 210,763 miles on it. Is the Schaeffers oil that good. I think so. They have a great web site to check out.

  12. #12
    Bob the Builder says: 88Nightmare's Avatar
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    Quote Originally Posted by Old Guy View Post
    Most things now are coming with synthetic, both for the improvement in MPG and life of the equipment it is put in.
    Dex VI can have trouble in the Allison because it's viscosity degrades too much over time. For the original poster's vehicle, Dex 3 or Transynd are the two best options for the transmission.

    At some point in production, Allison started building their transmissions to have their seals compatible with Dex VI, however the older ones were not compatible. You could call Allison and give them your transmission serial number and they can verify what seals were in it: 1-800-252-5283
    Quote Originally Posted by pOrk View Post
    All democrats like to work on wood, zing!
    The democracy will cease to exist when you take from those willing to work and give to those that are not - Thomas Jefferson
    2008 Yamaha FZ6
    2005 Silverado 2500HD 4x4 duramax

  13. #13
    have pot, will stir WickedSix's Avatar
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    stock trans in our climate can benefit from torque drive and the extended drain interval. Modified trans most recommend the standard Dex fluid. The newer trucks use a low viscosity formulation to decrease drag and improve fuel economy

  14. #14
    have pot, will stir WickedSix's Avatar
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    Oh and I forgot Bobo is in janesville, I think he use to be on this forum. He does some awesome work so far as tuning as well

  15. #15
    Bob the Builder says: 88Nightmare's Avatar
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    Quote Originally Posted by WickedSix View Post
    Oh and I forgot Bobo is in janesville, I think he use to be on this forum. He does some awesome work so far as tuning as well
    I want his truck
    Quote Originally Posted by pOrk View Post
    All democrats like to work on wood, zing!
    The democracy will cease to exist when you take from those willing to work and give to those that are not - Thomas Jefferson
    2008 Yamaha FZ6
    2005 Silverado 2500HD 4x4 duramax

  16. #16
    The edge thats in my 06 doesn't seem to change anything i've run a couple tanks on the milage tune and a couple on the stock tune and seems to get within a few tenths of a gallon different. my 04 was tuned with efi live i was getting steady 21 in the summer and about 17-18 in the winter. but was also a 2wd ext cab srw shortbox truck
    2001 Trans Am WS6, Race car
    [COLOR="Blue"]2006 Tacoma Xrunner

  17. #17
    Bob the Builder says: 88Nightmare's Avatar
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    the 2wd will make a big difference.

    EFI live will be happening for me sometime next year
    Quote Originally Posted by pOrk View Post
    All democrats like to work on wood, zing!
    The democracy will cease to exist when you take from those willing to work and give to those that are not - Thomas Jefferson
    2008 Yamaha FZ6
    2005 Silverado 2500HD 4x4 duramax

  18. #18
    A regular know-it-all Tetris Champion Snake Champion Lasagna From Heaven Champion Mac Man Champion Mahjong. Champion Mini Putt 3 Champion Plastic Saucer Champion Ratman Ralph Champion Prince Valiant's Avatar
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    Gap the sparkplugs. That'll net you 2mpg right there.
    1979 Lil' Red Express -Officially the quickest "bolt-on" LRT in the country.
    1989 Shelby CSX #500/500
    The most powerful production Minivan, ever...

    Be sure to check out my weekly adventures on the second page of your Sunday Comics!

  19. #19
    Quote Originally Posted by Prince Valiant View Post
    Gap the sparkplugs. That'll net you 2mpg right there.
    Just had one of those replaced at the dealer. I gained a couple
    2001 Trans Am WS6, Race car
    [COLOR="Blue"]2006 Tacoma Xrunner

  20. #20
    How much you want for it?

    Quote Originally Posted by fly5150 View Post
    I have an edge tuner I took out of my truck, works great, and mileage increase. LEt me know if your interested.
    -Dave
    2012 Street Glide
    1971 Vista Cruiser 455
    2003 Duramax Dually Silverado 4x4
    1986 442

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