Duramileage

Discussion in 'GM Tuning' started by SFC Cobb, Jun 5, 2008.

  1. SFC Cobb

    SFC Cobb Jesus Freak

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    I got this link from another forum. Has anyone heard of this chip and if so what? Does anyone have any 1st hand experience with it?

    I have to wonder about the fuel mileage increase claims.:Chevy_anim:

    http://www.powerupdiesel.biz/category_s/1.htm
     
  2. RayMich

    RayMich New Member

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    I just read about this.

    Does anyone have any experience with this guy's tunes?

    He claims 4 to 7 MPG gain hand calculated, as well as a stronger "bottom end" power band with his DURAMILEAGE tune.

    He say on his website:
    He charges $395 to re-flash your ECM. Add $300 if you want him to program a replacement (pre-owned) ECM. That way you can keep your original ECM stock.

    A 7 MPG gain would be very impressive, but a little hard to believe. :shocked:
     
  3. CtChevy427

    CtChevy427 Active Member Staff Member

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    Last edited: Sep 23, 2008
  4. RayMich

    RayMich New Member

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    Thanks for the link Bill.

    The first guy in that thread (cowdoc) says that he did get more power, better than the Predator on 65hp, but the best fuel economy improvement he managed to get was maybe 5% or 0.8 mpg, not the 25 to 35% (or 4 to 7 mpg) promised. After two different tunes, he is getting his money back.

    The second guy (falcon58) says that he is now getting 18.5 mpg at 75 and 80, hand calculated and if he drives 65 he gets 21/22. Then, as an after-thought, he throws in that those are Imperial Gallons.

    Well, an Imperial gallon is 20% larger that a U.S. gallon. So if we correct his fuel mileage to US gallons, he is actually getting 15.4 mpg at 70/80 and 17.5/18.3 mpg at 65 MPH.

    Heck I'm doing better than that on my pure stock truck! So this DURAMILEAGE tune is "more bark than bite!"

    Cowdoc's reported results are much more believable because he actually took the time to correct his speedometer/odometer with a GPS.

    What I'm seeing is that many people who claim they are getting these unbelievable numbers are just taking the MPG numbers from the DIC (which usually is WAY OFF when a tune is added). Others may be hand calculating, but if they don't correct their odometer readings they are not getting an accurate number. If your odometer and speedometer are OFF by a mere 1-mph/1-mile at 50, most people will say "that's close enough". But in reality 1 mile in 50 means that your speedometer/odometer is OFF by 2% or more right off the bat. Add that to the fact that most people don't take the time to insure that they are filling their tank to the same exact spot every time and you can add a lot inconsistencies to your calculations.

    Diesel fuel foams a lot when being pumped into the truck's fuel tank, especially in the summer heat. This causes the dispensing pumps to shut off at different amounts of fill. Sometimes the difference can be as much a 1 gallon or more. Most people will only top off a couple of more clicks on the pump's auto shut-off and call it good, but if you want accurate fuel economy calculations, that is not good enough. You have to ensure that you fill to the same exact spot in the tank every single time, to get an accurate comparison.

    Additionally, all fuel dispensing pumps are NOT created equal. Not all of them will read a 100% accurate measure, especially here in the US where gas stations are NOT required to temperature compensate their pump, so in warm weather you are actually getting LESS BTU's per gallon than you would in cold weather out of the same pump. When you compound those inaccuracies with the fact that "Winter Blend" has less BTU's per gallon compared to "Summer Blend", plus not every refiner gets the same amount of energy from a gallon of #2 diesel fuel (there is even a difference from batch to batch from the same refiners), it is hard to get an accurate comparison, unless you control all possible variables. Most of us don't have the equipment or the time to run such controlled tests.

    A/C ON or OFF can mean as much as 7 to 10% difference in fuel economy. Ambient temperature; cross-winds/head-winds/tail-winds; traffic conditions; tire size, tread design, tread compound and air pressure, all can potentially make a huge difference.

    All these variables added to the fact that human nature tends to make a person more likely to want to justify their investment, especially if they spent a lot of money for the tune or aftermarket equipment, make it very hard to sort out fact from fiction.

    I have run very extensive tests (several thousand miles back-to-back) with calibrated equipment, and the best I have ever seen is an ACTUAL 5% improvement in fuel economy. This is only my own personal experience; it doesn't mean that others can't get better mileage with different tunes, etc.

    Depending on the price of the tune/tuner and the price of diesel fuel, the amount of miles and time required to recover that initial investment can be VERY LONG and may NOT be worth the hassle or the risk. Keep in mind that until you actually recover your initial investment from the savings, you are in the NEGATIVE with that purchase.

    In reality, the best "Bang for the Buck" I have gotten was by replacing the air filter element. My air filter element had over 29,000 miles on it, it still looked good and the gauge on the side of the air cleaner had never moved from the green, but my fuel economy had been consistently dropping over several months. That $60.15 +tax investment got me almost 3 mpg improvement. It paid for itself several times over during one single cross-country trip.

    I have NOT yet been able to find that "Magic Bullet" that will give me a consistently huge fuel economy improvement. It amounts to a combination of thing added to sensible pressure on the right foot that will get you the best fuel economy.
     
  5. btfarm

    btfarm Quarter Million Worth Staff Member

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    That plus taking advantage of available drafting when prudent gets me to 19-20.5 mpg out of my stocker with regularity.
     
  6. CtChevy427

    CtChevy427 Active Member Staff Member

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    Ray, you are correct about the fuel mileage points most of which people dont think of. I followed Cowdoc's information all the way to where he went with a Kennedy Diesel tune. I guess this Duramilage thing has been around for a bit found some more good reading on it.

    http://www.dieselplace.com/forum/showthread.php?t=227146
     
    Last edited: Sep 23, 2008
  7. RayMich

    RayMich New Member

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    Thanks Bill.

    Do you have any info about cowdoc's experience with Kennedy's tune?
     
  8. t2ch

    t2ch New Member

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    Ray, I can tell you about Kennedy's tune. I have the tow/perf custom tune and love it. I can get 20+ on the interstate around 70-75 mph empty. I also can get 12-14 mpg on the interstate pulling a 35' TT at 10,000lbs. Shifts great, smooth power and no problems at all.
    I do not believe there are any tunes that will net over 21mpg consistantly on a stock motor. Even the Diesel Power Mag had Tomac at 24mpg in the Challange and said he was drafting as much as possible.
     
  9. CtChevy427

    CtChevy427 Active Member Staff Member

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    Ray, looks like he got comparable numbers to what t2ch spoke to. I was able to find cowdoc's post regarding the Kennedy tune. Here it is. http://www.dieselplace.com/forum/showthread.php?t=254775
     
  10. RayMich

    RayMich New Member

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    Thanks for your reply.

    Those are very impressive numbers. I've read some good things about Kennedy's tunes. but I have ZERO experience with EFILive and obviously no personal experience with Kennedy's tunes, so I'm intrigued.

    Can you give us more information about your experience?

    Can you tell us more about your truck and what mods you have?

    Have you been running this Kennedy tune for a while?

    Did you have him recalibrate your speedometer for the larger tires and if so, how accurate is it now and do you correct your numbers for speedo error? Are these numbers hand calculated or from the DIC? If hand calc'd, how accurate is the DIC in your truck? (My experience with aftermarket programmers has been that they throw the DIC way off and they are generally quite a hassle to get good accurate speedo calibrations - but I don't know how EFILive handles that.)

    Are you able to fill your tank to the same exact spot every time when you have checked your fuel economy to ensure good consistency? I know that many times this not possible due to fuel foaming and other impatient drivers waiting to use the pump.

    Did you have John re-flash your ECM or did you get one of his replacement ECM's and keep the original stock unit? How is the driveability (i.e. performance, shifting, EGT, smoke, etc.)

    Are those number with the A/C ON or OFF?

    What kind of tire pressures are you running? What tires? Load Range?

    Have you upgraded your transmission?

    Are you using any kind of fuel additive?

    How do these mods/tune compare to the time when your truck was pure stock?

    Finally, how much was the tune? (Feel free to PM me if you don't feel comfortable posting this information)

    Sorry for all the questions, but those numbers are very appealing.

    Thanks for your time and patience with my questions.
     
    Last edited: Sep 23, 2008
  11. RayMich

    RayMich New Member

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  12. t2ch

    t2ch New Member

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    Keep in mind I carry about 300-500 lbs of tools and materials in truck boxes daily.

    John also said he dynoed the tune on a stock truck with stock exhaust and intake. The numbers where around 370 rwhp and 700 tq. I am thinking of dynoing mine for the hell of it and when or if I do I will let you know.

    Another thing about this tune is it comes on from idle. Most box tunes don't kick in until 1200-1500 rpm. Atleast Flashpaq and a few others anyway. There is no defuel or feeling of once the tranny learns the power either.



    The ease of this is great. I get the benefits of EFILIVE without the programming headache.

    Let me know if you have anymore questions.
     
  13. cowdoc

    cowdoc New Member

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    CtChevy427 invited me over to join this conversation so I will try to help. I noticed that t2ch has already responded but I will give you my take as well. I have gotten as high as 20.8 mpg on the interstate @ 72 mph, but I usually average right around 20. Most of my driving is on country roads @ 60 mph. I average 18+ with this type of driving. I am convinced that if I could stay at a constant 60-65 mph on a long trip I would average around 22 mpg, but who can do that. If you have checked out the threads that have been referenced here, you will know that all my numbers are hand calculated and GPS verified. Now i will try to answer you questions.

    Hope this helps.
     
  14. cowdoc

    cowdoc New Member

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    The Duramileage tune did give me some decent gains, but nowhere near the claims. I got low-mid 19's on the hiway and low 18's driving on country roads. I didn't have gauges at the time I tried it and I was a little nervous about the EGT's. They may have been fine but I was too chicken to chance it.
     
  15. CtChevy427

    CtChevy427 Active Member Staff Member

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    Cowdoc, thanks for stopping in and adding your experiance with the Duramilage. Welcome to DTR :cheers2:
     
  16. RayMich

    RayMich New Member

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    T2ch and Cowdoc, thank you for sharing with us about your experiences with the Kennedy ECM tune. It is quite refreshing to read all the good things you have said about your experience with John Kennedy and his company. That speaks volumes about John.

    Sound like you guys are just as meticulous as I am in documenting your test procedures and results. I'm glad to see that John is willing to work closely with you to help you get the best experience from your truck.

    It is interesting to read that neither one of you have noticed much difference in fuel economy between running with the A/C ON or OFF. I have seen as much as 1.0 to 1.4 mpg difference while running at 70 MPH during cross-country trips between A/C ON and OFF on my pure stock LBZ.

    Also, I have experienced a consistent 3/4 to 1 mpg loss when switching from the stock highway tread LT245/75R-16(E) tires to the larger A/T tread LT265/75R-16(E) tires. (All my fuel economy figures have been hand calculated and corrected for speedometer and tire error for every single gallon burned through this truck and all fuel fills have been to the bottom inside lip at the top of the fuel filler neck) I now have a little over 38,000 miles on the truck.

    One last question for you guys:
    Looking back at your total experience, and the fuel economy you got before the Kennedy tune vs your fuel economy AFTER the Kennedy tune, how much of an improvement did you actually get from your investment? If you have before and after numbers that would be great.

    Thanks again guys, I really appreciate your input.

    And Bill, thank you also for your contributions to this discussion.

    Best Regards.

    BTW, cowdoc, Welcome to the DTR forum. :biggrin5:
     
  17. t2ch

    t2ch New Member

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    Ray, I'm not positive with these numbers but when my truck was stock, I averaged 14-16 in city driving and if I was lucky I got 17-18 on the highway. You must take into consideration that I am not light on the right peddle.
    With the tune I avg 16 consistantly in city driving and on the highway I avg 19+ with some trips upwards of 21.
    My driving everyday consists of city and highway. High traffic and a lot of stop and go. My fuel consumption stayed between 13-15 mpg and with the tune it is 16-17.

    I believe every truck is different. I also believe the more miles that are put on a Duramax the better mileage will be.

    And welcome to the forum cowdoc!
     
  18. cowdoc

    cowdoc New Member

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    Ray,
    My pre-KD numbers were as follows:
    Hiway: 18.55
    Daily: 17.07

    KD numbers:
    Hiway: 20.11
    Daily: 18.61

    Improvement:
    Hiway: 1.56
    Daily: 1.54

    It looks like I gained a solid 1.5 mpg with the KD tune.
    The pre-KD numbers include stock, Predator 65 hp, EVO-1, and EVO-2 tunes.

    At todays fuel costs, it will take me 50,000 miles to pay for the tune in fuel savings. Since I put close to 50k a year on my truck, I will have it paid for in a year. I will keep the truck for another 3 1/2 years so for me it is worth the cost. If someone doesn't drive a lot of miles and/or plans to trade every couple of years I just don't see how it would be worth the cost.
     
  19. RayMich

    RayMich New Member

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    cowdoc,

    Thanks for your response. I fully understand your logic and justification for this tune.

    I've run some calculations of my own using the figures you and t2ch have posted and according to my driving requirements and using our current price for diesel fuel at $4.069/gallon, my break even point would be somewhere around 36,000 to 40,000 miles. Unfortunately business has been way down here, and so are the number of miles this truck gets driven per month now, so at the current rate it would take me over 3 years to break even. I'm not sure I can justify that expense right now.

    Thanks again for all your comments and advice. I really appreciate it.
     
  20. t2ch

    t2ch New Member

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    No problem , glad I could help
     

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