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Odometer Readings

Discussion in 'Gen 2 Prius Main Forum' started by bandgeek, Jun 3, 2005.

  1. bandgeek

    bandgeek New Member

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    Curiosity Question Here,

    I am currently on my second tank and at around 800 miles on the main odometer. I filled up at exactly 500 miles so that puts me right at 300 miles so far on this tank according to the main odometer. I also reset my MFD at the fillup. Here is where things get a little strange. The odometer on the MFD is showing about 10 miles less traveled. Do they run off the same calculations? (Perhaps the MFD uses GPS mileage as opposed to tire roll?) Why the difference? Does the displayed MPG use the MFD mileage or the main odometer mileage? Would this account for the difference in calculated MPG vs. displayed MPG. Maybe I am missing something somewhere.

    Any enlightenment would be much appreciated.

    Dan
     
  2. GSpozars

    GSpozars New Member

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    Odometer Reading & MFD have been +-5 miles

    We have 2 new 2005 Prius in the family, with 11K and 3K miles.

    We reset the Trip Odometer each time we gat gas in each car.
    The MFD Consumption vs. the Trip Odometer has varied by less than 5 miles, usually just 2 - 3 miles since we have had the cars.

    That is a rather small variance, but they must get the info. from different sources. They are very close but not always the same.

    The MFD Consumption miles does not reset to Zero until the car is driven away from the gas pump, but it never is more than one mile.
     
  3. efusco

    efusco Moderator Emeritus
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    1)Be sure your ODO is on the main ODO reading and not ODO A or ODO B.

    2)There will be a difference. You reset the MFD display yourself, but then it auto reset again once the tank reached the full mark and the wheels turned a full revolution after that. So, If you pushed the 'reset' at the pump, then pulled out into traffic and drove down the road at a relatively high speed the tank takes 30-60 seconds to show "full". Then, a few moments later, the MFD resets to ZERO.

    3)The Dash ODO reading will be the most accurate to follow over time. The ODO on the MFD is handier for calculating MPG tank to tank.
     
  4. KTPhil

    KTPhil Active Member

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    10 mile error from less than a minute of driving? Must be downhill...
     
  5. jeromep

    jeromep Member

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    Not to hover on semantics, but the "odometer" on the MFD is not an odo at all, but a tripometer, just like Trip A and Trip B on the dash. However, the MFD trip will reset itself after you fill up the tank and roll away. Also, the MFD trip doesn't ever get its mileage from GPS. You have to account for the fact that most Prius owners do not have package 6 and all the nav stuff, however we still have the MFD trip. It only makes sense that in all Prii Toyota would be pulling miles traveled from the same source rather than two different sources based on how the vehicle is equipped.

    Your discrepancy seems to be related to how you are resetting your tripometers with respect to the drive away from the pump and the vehicle's need to self reset the MFD trip and average MPG display.

    In short: MFD trip gets miles traveled information from same source as odo, Trip A, Trip B. MFD mpg average is calculated off from MFD trip and information provided about fuel consumption from the engine/HSD system.

    So, don't reset your MFD trip manually when you fill up. You will need to continue to reset regular trip before you leave the pump.
     
  6. Whiteyprius

    Whiteyprius Active Member

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    It sounds like you really know something about the odometer resetting issue. Why doesn't the owners manual tell you about such things. You say the MFD trip meter resets when you fill up? What constitutes a fill up - when the gas guage hits full after not being full? I appreciate your shedding some light on this myster!:D