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An AWD Prius?

Discussion in 'Gen 2 Prius Technical Discussion' started by jyl, Dec 22, 2008.

  1. jyl

    jyl New Member

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    What do you think the pros and cons of a AWD Prius would be.

    I was thinking the rear wheels could have electric hub motors, so they could be driven at low speeds (like, when struggling through snow, or in other low-traction conditions.) At higher speeds the electric motor would be declutched from the wheel, so there would be no parasitic drag. The ICE and main electric motor would continue to drive the front wheels only, and in normal operation with ample traction, the rear wheels would not be driven.

    This though came to mind because we have 6" of snow in Portland and my Vanagon can't struggle down our unplowed side street to the packed snow of the main road - despite snow tires and a bunch of shoveling. The Prius, also w/ snow tires, made it through okay. But if the snow had been any deeper, AWD would have been nice indeed.
     
    #1 jyl, Dec 22, 2008
  2. qbee42

    qbee42 My other car is a boat

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    Any deeper snow and you would need tracks on the Prius, not AWD. The Prius sits pretty low, so that would limit the advantages of AWD. The main disadvantages are increased cost, complexity, and additional weight.

    Tom
     
    #2 qbee42, Dec 22, 2008
  3. patsparks

    patsparks An Aussie perspective

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    Would you need to clutch the motors from the wheels, if there is no draw from the motors and the wheel bearings support the permanent magnet rotor. Acceleration would be very good.
     
    #3 patsparks, Dec 22, 2008
  4. qbee42

    qbee42 My other car is a boat

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    No, there would be no advantage to using a clutch.

    Tom
     
    #4 qbee42, Dec 22, 2008
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Highlander Hybrid and Lexus RX400h are practical implementations of hybrid AWD vehicles. They have similar drivetrains. MGR (a third electric motor) is located on the rear axle to power the rear wheels. The hybrid vehicle ECU determines how much power to allocate to MGR depending on the driver's power request and wheel slip.

    If an AWD Prius was ever released I would expect it to have a similar basic design.
     
    #5 Patrick Wong, Dec 23, 2008
  6. patsparks

    patsparks An Aussie perspective

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    Yes I know, it was a rhetorical question.
    But that's cool. :)
     
    #6 patsparks, Dec 23, 2008
  7. Tideland Prius

    Tideland Prius Moderator of the North
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    I'd rather have a bit more ground clearance. I've been scraping the bottom all weekend on the high bank between the tyre tracks.
     
    #7 Tideland Prius, Dec 23, 2008
  8. bat4255

    bat4255 2017 Prius v #2 and 2008 Gen II #2

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    I wonder what it would take to raise the suspension 1"-2", or if it's even feasible?
     
    #8 bat4255, Dec 23, 2008
  9. qbee42

    qbee42 My other car is a boat

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    Perhaps a suspension system that could be adjusted on the fly. That way you could stay low for good aerodynamics, but raise the ground clearance when the snow piles up.

    Tom
     
    #9 qbee42, Dec 23, 2008
  10. bat4255

    bat4255 2017 Prius v #2 and 2008 Gen II #2

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    #10 bat4255, Dec 23, 2008
  11. patsparks

    patsparks An Aussie perspective

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    Now we need to work something out for the front.
    Some Subaru and Crowns have air bag suspension on all wheels.
     
    #11 patsparks, Dec 23, 2008
  12. molgrips

    molgrips Member

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    The Lexus AWD system also allows for regenerative braking on all the wheels, which we currently can't do, so it'd be a good system. Could help equalise out the tyre wear.

    A big advantage I can see to adjustable height suspension would be the ability to lower the ride height when cruising, to reduce drag and increase fuel efficiency. While we're at it, why not electrically lowerable ground-effect skirts that pop up when you slow to manoeuvring speeds?
     
    #12 molgrips, Dec 23, 2008
  13. bat4255

    bat4255 2017 Prius v #2 and 2008 Gen II #2

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    #13 bat4255, Dec 23, 2008
  14. Tideland Prius

    Tideland Prius Moderator of the North
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    Well larger wheels would help with 0.5 to 1"
     
    #14 Tideland Prius, Dec 23, 2008
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