Do you LIE about your mileage?

Discussion in 'Gen 2 Prius Main Forum' started by macmaster05, Oct 25, 2009.

  1. macmaster05

    macmaster05 Senor Member

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    The MFD mileage and actual mileage (if you calculate it) vary by about 3-8%, and the actual is usually worse than the MFD. For example, my MFD read 54.9 mpg but after buying gas, I calculated that I only got 51.4 mpg. No problem, now I know.

    So my first question is;

    1. Do you calculate your ACTUAL mileage?

    2. If you do, when you tell people your mileage, which one do you usually report (including these forums). Do you lie?

    Thanks
     
  2. PriusRos

    PriusRos A Fairly Senior Member - 2016 Prius Owner

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    Yes, I track my mileage and no, I don't lie about it. The problem when talking about it to lay people though is it's kind of hard to explain. If I say I get around 45mpg overall, which is what I am getting, it isn't very impressive. So I normally say I get 40s in town and anywhere from 50 to 60 on the highway -- and that's true.
     
  3. warrior

    warrior New Member

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    I am willing to take a polygraph test!!!!:)
     
  4. Priusphev2010

    Priusphev2010 New Member

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    I have not calculated my milage manually yet. Based on what I read in the Forums here, most people believe that fuel economy changes slightly after the "brake-in" period. I'm almost there with 4500 miles. After that I will crunch some numbers manually. Currently my MFD shows 54.4, but I would be hesitant to tell people that, especially if they do not own a Prius. Since I got my Prius, I've had to re-learn to drive. I drive a lot more conservatively now. It occurs to me that if I put one of my buddies behind the wheel of my car, they would get a lot worse MFD and it would look as if I'm making up my own numbers. Slippery slope.
     
  5. Matt Herring

    Matt Herring New Member

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    I report my mpg as MFD minus 2% as that seems to be the accepted adjustment for Gen II mpg reporting. Over 25 tanks my calculated vs. MFD shows the MFD at 1.76% optimistic so using MFD minus 2% is pretty close to accurate...actually shorting myself a little. Others on this site have tracked hundreds of tanks in Gen II's and report MFD minus 2% is pretty close to accurate for their lifetime consumption as well.

    If someone would ask me tomorrow what my lifetime mpg is I'd say right around 59 mpg.
     
  6. paprius4030

    paprius4030 My first Prius

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    I always say, "It usually is.....50, except during the winter" That way it's the truth...usually:doh:
     
  7. fuzzy1

    fuzzy1 Senior Member

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    Are your referring specifically to GenII (2004-9) models? I had understood those to have fairly accurate MFDs. But the bladder in that generation causes pump calculations of single tanks to be very erratic.

    The error magnitude you mention is much more typical of 2010s, such as mine. On forums and in person, I always report pump mpg, not the higher display mpg.

    Except to those who open with anti-hybrid hostility.
     
  8. paprius4030

    paprius4030 My first Prius

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    What do you tell the anti-hybrid hostile people? That you get 80mpg's LOL:eyebrows:
     
  9. blueumbrella

    blueumbrella Member of Prius Regeneration

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    I believe I may have told a few small ones over the years, but I cannot even imagine stooping so low as to claim better gas mileage then I was getting. This is nothing less then a "turn in your smart key" penalty. :eek:
     
  10. Celtic Blue

    Celtic Blue New Member

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    Mine differs by ~0.8% longterm. The GenIII has a large error, not the GenII.

    Yes.

    I tell them both, since they are the same.

    No, I don't lie.
     
  11. cycledrum

    cycledrum PSOCSOASP

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    1. Yes

    2. I tell people what my MFD is currently reading and tell them calculated too sometimes.

    Calculated is often just a bit over 1 mpg less than MFD.

    Last calculated tank at 405.6 miles with 7.631 gal = 53.15 MPG . Amazing.
     
  12. hill

    hill High Fiber Member

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    If the mfd is 5% inacurate (sometimes) does that mean I'm only getting 74mpg? ... you take a polygraph ... I'll take a photograph:

    [​IMG]


    Sometime I tell people I only get 50mpg ... just so I don't sound smug.

    :D

    .
     
  13. fuzzy1

    fuzzy1 Senior Member

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    Would that really be a lie? If it weren't for the no-baiting declaration from the moderators, I'd be tempted to post this actual trip segment to the TDI Tank Wars board: :D
    [​IMG]

    For the anti-hybriders, I give a real displayed figure from one of my recent average-or-better full tanks -- 57 or higher.

    FWIW, my lifetime (9300 miles) display error is currently 4.9%.
     
  14. Tideland Prius

    Tideland Prius Moderator of the North
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    Nope. Don't need to. I have a spreadsheet if anyone wants to challenge my claim (both MFD and calc'd numbers). It also helps that my best mpg has minimal differences btwn MFD and Calc'd

    [​IMG]

    Record average FE. Calc'd FE on this one was 3.92L/100km

    [​IMG]

    This one is my record distance on a tank. Due to rounding differences, the trip odometer read 902.1k but the MFD was still at 901.
     

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  15. JimboK

    JimboK One owner, low mileage

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    As others suggest, most of us who have tracked it for an extended period show a variation of less than 3%. I've tracked it for two years and it's about 2.5%.
     
  16. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I say some variation on this " Best tank was 52, worst was 39, but I average 42 MPG." and I do. (Temporarily, I am getting 47, but it can't last. Mississippi will get hot again)
     
  17. snead_c

    snead_c Jam Ma's Car

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    No. Lying would cause the nose of my car to grow longer and thus create garage parking problems...as well as blemish the stellar reputation of my Prius.;)
     
  18. swi66

    swi66 Member

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    For about the first 6 month's of ownership I recorded both what the car said and what I got.
    I thought it was pretty accurate seeing as how can you truely tell if the pump is accurate? (Yeah, I know gas pumps are supposed to be certified, but computers in these pumps can be programmed wrong too).

    I consistantly get over 50 with both what the car said and what I calculated.
    That was after the first 1000 miles.

    I do get a little under 50 during the worst winter weather, so I have no reason to lie!

    There are still some who do not beleive me.
     
  19. patsparks

    patsparks An Aussie perspective

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    I quote the MFD and I refer to my metro mileage. If I convert to MPG I use US MPG not the UK standard which most people here refer to. If I told people I get about 65MPG they would think I was lying so I use US figures to quote 55MPG.
     
  20. redrockprius

    redrockprius redrockprius

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    Why lie (unless you're training to be a politician)?

    I've been tracking the actual gallons added over the 19,000 miles since I bought the car. I also calculate the gallons that would have been used for each filling, based on the reported mpg between fillings. My actual mileage (actual gallons purchased divided by total miles traveled) over the 19,000 miles is 48.32 mpg. The MFD reported mileage (sum of all calculated gallons consumed divided by total miles traveled) is 49.60 mpg. These data indicate that the MFD reports that mileage is almost 2.7% better than actual.
     
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