06' Duramax mpg

Discussion in 'Trucks and Trailers' started by UrbanGreen, Mar 4, 2008.

  1. UrbanGreen

    UrbanGreen LawnSite Member
    Messages: 162

    I have a 06' 2500 duramax, 4x4, allison tran. Looking thru some of the old threads I have read of some people getting anywhere from 15mpg to 22mpg pulling heavier loads than I pull with their duramax. I normally pull about 4k lbs (open trailer/ equipment) and sometimes a 14' dump trailer loaded (not quite sure on weight). My duramax doesnt even know that I have a load behind it I think because I get 10-12mpg no matter what.
    I was wondering if anybody knows of what I could do to improve my mpg. I am not sure with all of hundreds of bolt-ons and chips that out there. I would like to know what others have tried and liked or disliked. Thanks
  2. PLM-1

    PLM-1 LawnSite Bronze Member
    Messages: 1,640

    That's pretty low. Clean air and fuel filter? Larger tires? My 04 LB7 averages 16-17 mpg mixed city/highway with a combo of towing and not riding on 265's. Don't forget we are on winter fuel so fuel mileage reflects that.
  3. UrbanGreen

    UrbanGreen LawnSite Member
    Messages: 162

    when i went from factory tires to 285s i lost 2 mpg but got that back with a new intake. ikeep fuel filters and oil filters changed every 7k. I use GM filters, do you recommend something else?
  4. PLM-1

    PLM-1 LawnSite Bronze Member
    Messages: 1,640

    And air filter is ok? If your truck is under warranty I would take it to the dealer and explain what's going on. You may have bad injectors (which i haven't heard of on an LBZ). any white smoke?
  5. UrbanGreen

    UrbanGreen LawnSite Member
    Messages: 162

    I have already had GM look at it. They did find that my emissions sensors were screwed up and the had to reprogram it. Afterwards I told them I was still getting lousy gas mileage and they told me they couldn't find anything wrong. They even rechecked the computers and said everything was ok.
  6. UrbanGreen

    UrbanGreen LawnSite Member
    Messages: 162

    As far as smoke, before they did the first reprogram it was smoking. But now just a little black smoke if you really have to get on.
  7. Lawnworks

    Lawnworks LawnSite Fanatic
    from usa
    Messages: 5,407

    I think it is b/c most people lie about there mileage or don't actually compute it by hand. They are a flat out liar if they say they get 22mpg while pulling anything. I have an '04 Duramax and I barely get 16 pulling nothing.

    GSPHUNTER LawnSite Senior Member
    Messages: 311

    This is pretty much the truth. I don't know why, but it does seem like people always want to overstate their mileage for whatever reason. I've got an '01 Dmax that gets 16-18 with all kinds of driving. I've never really noticed it go below that, but if I'm real nice on the highway, I can get about 20 mpg. That is going about 60-65 mph though.

    The newer diesels aren't turning out near as good of mileage as the older ones. They got into power races between the big three diesel trucks and it killed the high mpg quality of diesel pickups. My dad's 07 Classic Dmax only gets about 15 mpg.

    Try some Howe's or Lucas fuel additive. This adds some lubrication to your fuel, which new diesel few lacks in. I notice some mpg change when using it, and it's supposed to be good for your fuel components. Also, it will pay for itself in fuel savings.

    Good Luck.
  9. TXNSLighting

    TXNSLighting LawnSite Fanatic
    from DFW, TX
    Messages: 6,463

    Which duramax do you have? that will make a difference. LLY or LBZ? I have an 07 LBZ and you have to make sure the fuel filter is changed pretty often and the air filter is clean. mine gets 19 hwy. alot to do with the 6 spd allison. bout 15 in town.
  10. UrbanGreen

    UrbanGreen LawnSite Member
    Messages: 162

    I have the 6.6l LBZ dmax. I change the fuel filter every 7K, do I need to change it more often? When I drive on the highway the I have gotten going about 65mph was 13-14mpg. Something cant be right. Im not really expecting 22mpg but something a little better than what I am getting.

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