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Trying to keep Prius from using MG or ICE downhill

Discussion in 'Gen 2 Prius Technical Discussion' started by ukr2, Feb 14, 2007.

  1. ukr2

    ukr2 Senior Member

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    While Driving in slow traffic on a slight downhill, when I released the brake without pressing the accelerator, I wanted to coast downhill, but the Prius uses the Electric Motor, MG. If I press the brake the MG stops driving the wheels and regens the battery.

    I shifted to B, but it still used the MG when I released the brake.

    Why does the Prius use any energy to move the vehicle when in the B mode?
     
    #1 ukr2, Feb 14, 2007
  2. hobbit

    hobbit Senior Member

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    #2 hobbit, Feb 14, 2007
  3. efusco

    efusco Moderator Emeritus
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    basicly that's the hill-holder function at speeds less than ~7mph. It's a very tiny drain at that speed.

    Read Hobbit's link for B-mode info...basicly though you shouldn't ever need to use it on any but the very longest highest steepest mountains.
     
    #3 efusco, Feb 14, 2007
  4. qbee42

    qbee42 My other car is a boat

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    The Prius HSD is designed to mimic a "normal" engine and drive-train so as to not be confusing to all of us well-conditioned drivers. When you let up the gas pedal on a conventional car, engine drag retards forward motion. The Prius mimics this by applying a little regen braking in the same situation. To avoid this, press the gas pedal slightly. There is a sweet spot without regen or thrust where the car will just glide.

    Tom
     
    #4 qbee42, Feb 15, 2007
  5. Earthling

    Earthling New Member

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    On a slight downgrade through a town, I like to apply slight throttle to put the Prius into electric mode. Electric mode is often useful at maintaining speed on downhill grades. This is a good thing, as I can travel for a mile or more using no gasoline at all.

    Harry
     
    #5 Earthling, Feb 15, 2007
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