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Did reprogram affect your mileage?

Discussion in 'Gen 2 Prius Main Forum' started by Azor, Feb 27, 2006.

  1. Azor

    Azor New Member

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    Wow - 56 for highway is great. Good for you. I fear with my long trip from Maryland to Florida and than back up to Maryland in temps between low 30s and high 70s and still nothing higher than 45 mpg (not to mention a total of 10 thousand miles I've put on the car since the reprogram), I'm convinced the gas mileage had permanently been reduced. I will soon be talking to the dealer about what version of the program I do have and insist on the latest if it is an older version. I would hope the mileage can't get worse with latest program...
     
  2. V8Cobrakid

    V8Cobrakid Green Handyman

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    2004 Prius
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    N/A
    I've noticed.. since.. uh.. two days ago, that the car uses the electric system a lot more during warmup. It also uses the battery a lot more during normal use. It's all a lot different than the previous programing. The car does tend to keep above 40mpg a lot easier. When i cruise it gets in the 50's and 60's pretty easy.. but no 70 or 80mpg periods anymore "yet"... i've only been doing short trips to and from work. about 4 miles. (roughly 5 minutes, if that)

    my warmup time is a road about 2.5 miles long. No stop signes with a speed limit of 35mpg. All slightly down hill with a very small rolling set of hills. I think its the perfect warmup spot. I usually get 40mpg on the first bar, if not a little tiny bit higher. So.. warmup i still about the same MPG wise.. but i can go faster than normal and still achieve these numbers.

    the system doesn't seem to regenerate as well as it did before. Coasting brings some bars back, but i used to be able to put the battery in a green state at the end of my warmup (2.5mile) stretch of road. hmm.. i'll have to try again today.

    I noticed i can "no arrows" pretty easy. I can also do that pulse technique.. or was it the glide technique.. ok.. i need to look up the definitions again (no energy to or from battery)... except in warm up time.. all arrows go from the battery.

    so yeah.. it's good.. i guess. A lot more test to be done.
     
  3. devprius

    devprius /dev/geek

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    I had my reprogramming done back in January of this year. Immediately afterwards I noticed a reduction in gas milleage, just as others have. Now, after about 6 or 7 tanks (and 900 mile roudtrip to SoCal), I've noticed that my milleage has not only gotten back up to what I used to see, but appears to have improved overall. I have not altered my driving habits, nor have I radically changed the way the car is setup (tire pressure, amount of oil filled, etc). Whereas I used to see 42 or 43 on the MFD, I'm now seeing 44 to 47.
     
  4. KTPhil

    KTPhil Active Member

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    Yes, that's the one. Here is a link to the Toyota document:
    http://priuschat.com/forums/files/el002t05.pdf

    It is only for 36K miles, but you might appeal and see if corporate will reconsider, especially if the problem manifested itself immediately follwoing your reprogramming. Perhaps they spiked power or some other step that put it over the edge?
     
  5. Azor

    Azor New Member

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    Ok - here is the deal. I just spoke with corporate and it seems there was a campaign about people losing mileage after the reprogram. Unfortunately, because it was a safey issue, I can not get my old program back. (no surprise)

    The program version issue had nothing to do with the car program but the scantool that the dealer uses to scan the car. They have the correct version (3.0), thus no damage was done to my car from that.

    One thing of interest I learned is that there is a bladder in the prius gas tank and that temperature may affect the actual volume in a full tank. However, since I have calculated mileage the exact same way before and after the reprogram in a wide diversity of temps - that becomes a relative error and would not account for the huge difference in my ranges before and after the reprogram.

    It is clear that the gas engine behaves differently and the dealer seems to agree with that conclusion.

    As for the display:
    I will know for sure tomorrow, but Toyota made it seem like they were paying for the ~$500 display and I would pay for the ~$100 labor. That seems fair especially since most likely this problem wasn't associated with the reprogram (plain bad timing).

    I just have to constantly remind myself that I am still getting better gas mileage than other cars...sigh

    Thanks for everyone's input!
     
  6. Tempus

    Tempus Senior Member

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    That's what seems to be standard for after warrantee MFD failures. Toyota comps the refurbished display, and you pay the install labor.

    Of course, it's not that hard an install. I'm just waiting for someone to say "Ok, give me the display, I'll install it myself" :)
     
  7. SirGreen

    SirGreen New Member

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    I just got my 06 Prius on Feb 4th 2006.
    How do I know what programing I have,
    and if I need to be reprogramed?
    also after 1400 miles I am just at 44 MPG
    Living in the Richmond Virginia area.
     
  8. KTPhil

    KTPhil Active Member

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    2006 models do not need reprogramming. It was 2004 and early 2005 models only.