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Avg MPG counts down while idle

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by Jared Leibowitz, Jul 27, 2023.

  1. Jared Leibowitz

    Jared Leibowitz Junior Member

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    Hey I have a 2016 Prius that I just noticed today it counts down on my avg MPG while parked and idle with the AC on. It counts down every 5-10 seconds by 0.1

    for example it’ll show 53.5, 53.4, 53.3, etc.

    I also just today had an issue where when I’d accelerate after a red light my car would take a second to start moving. This issue only happened twice today but hasn’t happened the rest of my commute home.


    Any ideas why this is happening?
     
    #1 Jared Leibowitz, Jul 27, 2023
  2. JohnPrius21

    JohnPrius21 Junior Member

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    #2 JohnPrius21, Jul 28, 2023
    Mendel Leisk and bisco like this.
  3. bisco

    bisco cookie crumbler

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    what's the ambient temp? maybe it is anticipating mpg loss due to battery protection from heat
     
    #3 bisco, Jul 28, 2023
  4. rjparker

    rjparker Tu Humilde Sirviente

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    Your burning battery energy which has to be accounted for since there will be no corresponding regen you get when moving. AC sucks it up.
     
    #4 rjparker, Jul 28, 2023
    Last edited: Jul 28, 2023
  5. fuzzy1

    fuzzy1 Senior Member

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    Is the engine running? If so, then fuel is being burned, but miles are not being added, so therefore the MPG is falling. That is the basic arithmetic.

    The lower the miles displayed on this trip meter, the faster the displayed MPG can fall.
     
    #5 fuzzy1, Jul 28, 2023
    Doug McC likes this.
  6. Doug McC

    Doug McC Senior Member

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    The most effective way to get really bad gas mileage is to simply start your car and never move it. You can even get it to the point that you get a whopping 0 mpg, and you don’t even need to leave your parking spot.
     
    #6 Doug McC, Aug 19, 2023
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