Chevy Duramax MPG - Diesel mpg?

Discussion in 'GM Diesel & DuraMax' started by freddie, Jul 5, 2009.

  1. freddie

    freddie New Member

    I just recently purchased a 2005 duramax 4x4 with about 65000mi. I believe that it is the 6.6l turbo. It has a few up grades like a k&n cold air intake and a banks monster muffler. It seem to be getting about 15mpg. And I don’t think that is very good but I am not sure.

    So I decide to run some lucus oil through to see if that may help but I have not run that tank out yet. Is there something else that I may need to check on the truck that could be causing the lack of mpgs? Or is this possibly as good as it gets?
  2. Joeairforce

    Joeairforce New Member

    That's about what I get around town in my 04.5 that I'm trying to sell, which is the same engine as yours. I can get up to 21 mpg on the interstate though. Of course mine also has a Banks Six-gun on it too.
  3. 1st Synthetics

    1st Synthetics New Member

    15-20 is about normal for the Duramax LLY motor. Do you have your foot in it a lot? I know if this is your first diesel that you probably do like all others enjoying the power:glasses:. What size tires are you running?

    If want to keep the truck running with no problems ditch the K&N filter. It is the worst thing you could have on a turbo diesel and will wear out the fins on the turbo. Also Lucas oil products are junk and I do not suggest you use them. If you really want to boost up your MPG all you need to do is exhaust from the downpipe back and a tuner. EFI Live is the best on the market but not for beginners. PPE or edge are also good choices.

    If you want a good air filter send me the part number off that K&N and I will cross refrence it and hook you up with a AMSOIL EA filter that will offer much better protection.
  4. vncj96

    vncj96 New Member

    my uncle can get over 24 mpg all day long on his 05
  5. freddie

    freddie New Member

    I am running 285/75/16 bfg at's. The part number off the k&n air filter is F041A12. I do need a new one because the fins on the air filter are messed up. This is my first diesel so I do think that my foot may have some to do with the mileage. Thanks alot for all of your insight!

    Where would be a good place to purchase the PPE or edge products or maybe even the banks six gun? Seeing how I already have the banks monster muffler.
  6. 1st Synthetics

    1st Synthetics New Member

    I'm not finding that number F041A12, even on K&N's site. Can you send me or post a picture of the filter? Is it cone style?

    Look at AMSOIL's universal filters here. click on See detailed EaAU specifications and photos and see if one matches yours.

    I'd get the EDGE race it is one of the best out there. I have the Edge Juice with attitude and like it, but would like to go to the race.
  7. ki4kma

    ki4kma New Member

    Got 05 and we get about 18-21 riding around and about 13-15 towing
  8. DamnBigPapa

    DamnBigPapa New Member

    Your foot needs to get used to the diesel

    if you are new to the turbo diesel platform ... you'll find that you almost need to re-learn how to accelerate. I'm sure by now you have realized that if you slam it to the floor, the response is a lot different than with a gas V8.
    let the boost do the work. The old "act like there's an egg under the pedal' works well. I tried to keep my boost levels low and see what impact it had on mileage ... it was huge. Ease into the gas and let the turbo do the work. If you mash it, you might as well have a hole in the tank.
  9. dsfloyd

    dsfloyd New Member

    look into the 6 gun from banks. Great products. Also a light pedal is always good for the mileage
  10. tattooed4life

    tattooed4life New Member

    sct also makes great programmers.
  11. gt1009

    gt1009 New Member

    I got 20 in my old 6.2 k5 around town. Open up the exhaust and intake and it will work wonders. Combine that with easy acceleration and you should see 20, even with the emissions gear.
  12. DamnBigPapa

    DamnBigPapa New Member


    I use the Edge juice with the attitude controller display. The display helps out by showing you some useful numbers like boost, EGT, Temp, etc, etc. Bully Dawg and Banks have similar products. Diesels make power by adding fuel, so the higher the setting ... less mpg. Changing my driving style did more than anyhting though.
    The open (cold-air) intake didn't have any affect on my mileage, but it did drop my EGTs by about 120 deg under load on average.
  13. dwill3015

    dwill3015 New Member

    Sorry to reply so late but there are some great in-expensive programmers out there that work awesome like the Diablo Sport and the Quadzilla. I bought my quad for under $300 and has helped me out a bunch for mileage, speedo calibration for running larger tires), performance (5 tunes to choose from), DTC reader, and diagnostics scanner (found I had a bad injector before the dealer did). Later down the road I want to get EFI Live and do some custom programming on my own.
  14. 09SLE

    09SLE New Member

    Got a consistent 18.75 on a '95 Tahoe turbo diesel. City or highway.
  15. bricssig73

    bricssig73 New Member

    diesel mpg

    hi all,

    Question into what turbo and intercooler is the best to use for the 5L diesel in DARWIN.




  16. quadasteer_03

    quadasteer_03 New Member

    My dad gets 20+ with the diablo driving... Towing a 25ft camper at 75 mph he gets 16mpg... Its 04.5 gmc 6.6
  17. mrmanners

    mrmanners New Member

    Good fuel additives are a must. There are varying opinions on which is best but you want to stay away from anything with alcohol in it because it will dry things out too much. You should also consider cetane booster. Most ULSD have only the minimum cetane in them which I believe is 40. The cetane will help with combustion which will improve performance and fuel economy too.

    I use AMSOIL additives and have had good success.
  18. ChevyFan

    ChevyFan Administrator Staff Member

    What's the average MPG on here for Duramax owners?
  19. Joeairforce

    Joeairforce New Member

    During the 2 years I had mine, my average was 15.67 mpg over the whole 2 years.
  20. 1st Synthetics

    1st Synthetics New Member

    Mine is around 13 overall that is pulling my trailer and plowing snow included. Normal driving city/highway is around 16.

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