Driving in the Snow = B Mode?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Skateruk, Nov 14, 2013.

  1. Skateruk

    Skateruk Member

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    I am a new owner of a 2007 Prius and as the snow will soon be here, will driving in B mode rather than D provide greater traction?
     
  2. eXodus

    eXodus Junior Member

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    As far as i know the B mode is the "engine Brake" mode.
    So if you are -for example- driving down a mountain with the gear in D you will be accelerating even without the throttle pressed, if in this case you have it in B the car will be braking on it's engine/ generator/ electric motor.

    As far as i can see the only advantage you'd have with B mode in the snow is when you release throttle on a flat (or nearly flat) road that you will be slowing down gradually without the wheels losing traction.
    But then again, there's electrical systems to prevent the wheels losing traction aswell.

    Also if you have cruise control, this won't work when it's in the B mode.
     
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    No. It exists for 2 reasons: US Federal law requires all transmissions (with more than one forward gear ratio) to have a mode with more engine braking, and to help you keep the brakes cooler on long steep descents.

    B under the D in the Drive gears? | PriusChat

    - http://www.gpo.gov/fdsys/pkg/CFR-2011-title49-vol6/pdf/CFR-2011-title49-vol6-sec571-102.pdf
     
  4. john1701a

    john1701a Prius Guru

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    "B" can be effective when you have to deal with very slippery curves, since it serves as a means of slowing the car without activating the brakes on the wheels. So, there is a small advantage. But the use is quite limited.

    You'd take an efficiency hit if you used it all the time too, since that absorbs kinetic energy rather than the generator. Fortunately, you don't even have to look down to engage it. Just pawing the dashboard will do the trick.

    In other words, give it a try sometime (like when on fresh snow), but don't drive with "B" routinely.
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    (This is just my opinion)
    Shifting to L as a traction control trick worked on Rear Wheel Drive vehicles because it only slowed down the rear wheels. Having drag at the back of the car helps keep the car pointed forward. (often a good plan)

    In a Front Wheel Drive vehicle like the Prius, using the friction brakes is the way to get drag on the back wheels. (If the parking brake was a hand brake, it would be even better as it only uses the rear brakes)
     
  6. Britprius

    Britprius Senior Member

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    Now forgive me for turning this on it's head, but the OP asked if putting the car in B would provide better traction. Looking up the word "traction" in the Oxford English dictionary gives the definition as to draw or pull and on that basis I say putting the car in B mode will not improve the traction because this is the job of the traction control system. The ability to draw or pull the car forwards.

    John (Britprius)
     
  7. Bingee

    Bingee Member

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    No B won't give you better traction
     
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