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'B' position for engine braking...?

Discussion in 'Gen 2 Prius Main Forum' started by pearsonrj, Jun 30, 2005.

  1. pearsonrj

    pearsonrj Junior Member

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    The 'B' gear selection is used when going downhill to control vehicle speed using engine braking, right? Or does it use the motor to recharge the HV battery instead? I've read in other posts that using 'B" yields better fuel economy, but how can that be if it uses engine braking and not regen?
     
  2. kirbinster

    kirbinster Member

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    My understanding is that "B" will actually reduce your mpg somewhat, but will save you from riding the brake during long downhills. It uses the ICE with no ignition to add increased drag to slow you down. Under most conditions there is no reason to use this mode.
     
  3. aaf709

    aaf709 Ravenpaw of ThunderClan

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    Right. You'd use the "B" when you're going down a long hill, much the same way as you would shift to a lower gear in a regular car. It's not good to use if you're simply coming to a stop, and it's not going to help your fuel economy.

    Here in San Diego, there is no place to use it. If I went into the mountains, maybe.
     
  4. priusham

    priusham New Member

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    As stated in countless previous threads, it's used going down a long, steep mountain-type road.

    I used mine extensively driving back to Michigan when I bought my 2004 last summer in California. I NEVER used it after that.

    Our 2005 Prius has used the B mode ONCE - driving down from the top of the mountain at the NC/TN border in the Smoky Mountain National Park.
     
  5. SDiego

    SDiego New Member

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    Here in San Diego, maybe going down texas st. or coming back from Borana Casino, those have some steep hills..
     
  6. aaf709

    aaf709 Ravenpaw of ThunderClan

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    <div class='quotetop'>QUOTE(SDiego\";p=\"103917)</div>
    Yeah, Texas street did come to mind, but I generally avoid that hill and I haven't been to Barona in her yet. When I rented a Prius to take a trip to Julian, I didn't use it on the way home. Maybe I should have.
     
  7. chasabel

    chasabel Junior Member

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    Here's my experience using "B" Mode.
    I filled up in Greencastle, PA and headed West to McConnellsburg, PA.
    At the beginning of Tuscorara MT on Rt 16 about 13 miles, my MFD was reading 52 mpg.
    At the top of the MT (about 3 miles) it had dropped to 43 mpg and the
    battery was down to 2 bars.
    I shifted to "B" Mode and used it all the way down the mountain,
    again about 3 miles.
    When I got into McConnellsburg the MFD was reading 53.5 and the battery
    was green.
    Doesn't sound to me like you get less mileage using "B" Mode.

    Charlie
     
    Griff Derryberry likes this.