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Computer MPG higher than what I calculated

Discussion in 'Gen 2 Prius Technical Discussion' started by Kindke, Sep 12, 2018.

  1. Kindke

    Kindke Member

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    Vehicle:
    2017 Prius
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    Business Ed. Plus
    The computer shows me to be getting about 58-60 mpg, .... however when I calculated my mpg from miles since last fill up divided by fuel pumped into tank it only comes out at 49 mpg.

    Im not sure whats going on here however the speedometer of the car is very over-calibrated so this might be to blame. For example the speedometer will me show me to be doing 40mph when the GPS on my phone tells me its only 35mph.

    There difference is greater at higher speeds, the cars speedometer at 80mph is only about 72mph according to the GPS.

    Unless my car is screwed? Its a UK 2008 reg
     
    #1 Kindke, Sep 12, 2018
  2. bisco

    bisco cookie crumbler

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    yes, toyota programs the computer to make you smile whilst driving, and cry when filling up.

    the difference is usually less than yours, but may be made up over several tank averages.

    also, make sure you are running the correct diameter tyres
     
    #2 bisco, Sep 12, 2018
  3. Salamander_King

    Salamander_King Senior Member

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    Prius has been known to display optimistic mpg. My Gen3 always showed about 6-7% better than calculated mpg. My Prime when EV is not factored in still shows about 5% better mpg. Your case seems to be bit too much of variance. Or older Gen2 Prius had more of difference than newer ones?
     
    #3 Salamander_King, Sep 12, 2018
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