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How much drag does the antenna cause?

Discussion in 'Gen 2 Prius Fuel Economy' started by burritos, Aug 2, 2007.

  1. burritos

    burritos Senior Member

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    I'm sure it's miniscule, but my honda accord has it's antenna in the windshield. Maybe future prius's should do that.
     
  2. catgic

    catgic Mastr & Commandr Hybrid Guru

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  3. TheAnnoyingOne

    TheAnnoyingOne New Member

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    <div class='quotetop'>QUOTE(burritos @ Aug 2 2007, 10:15 AM) [snapback]489357[/snapback]</div>
    Depends on which station you are listening to. If it's heavy metal the drag will increase :D :blink: :rolleyes:
     
  4. Rae Vynn

    Rae Vynn Artist In Residence

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    We swapped out the antenna for the shark fin, and I gained 2 MPG* :D

    The antenna has this spiral wire on it, which causes the airflow to spin around it, creating a vortex. As the antenna is pointing back, this vortex is actually creating a vacuum effect, which is increasing drag. It's sucking the gas mileage right out.

    Oh, and the shark fin is cuter.

    *j/k
     
    offib likes this.
  5. Godiva

    Godiva AmeriKan Citizen

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    <div class='quotetop'>QUOTE(Rae Vynn @ Aug 3 2007, 12:13 AM) [snapback]489806[/snapback]</div>
    Mine has even more drag as I have a "lightbulb" that says "hybrid" on the end. Great for spotting in parking lots. But I'm sure it adds even more drag. I still like it more than a sharkfin. After all....where would I put my lightbulb?
     
  6. skandale

    skandale Member

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    <div class='quotetop'>QUOTE(Rae Vynn @ Aug 3 2007, 07:13 AM) [snapback]489806[/snapback]</div>
    From what I've heard, the spiral wire on the antenna is actually to decrease the votrtex behind the antenna.

    If you look at tall industrial smoke chimneys, you will se they have spirals as well. This is to disturb the wind so it does not form a vortex behind the chimney. Before they learned to do this, heavy winds could set chimneys into a resonans vibration tearing them apart.


    Stein
     
  7. jiepsie

    jiepsie New Member

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    <div class='quotetop'>QUOTE(burritos @ Aug 2 2007, 07:15 PM) [snapback]489357[/snapback]</div>
    I remember reading about a 1% MPG impact somewhere. Can't find a reference though. At high speeds, it might be measurable. Just try holding the antenna in your hand, out the window, at 80 mph and feel the drag. You'd be surprised.
     
  8. hycamguy07

    hycamguy07 New Member

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    Thats the best one yet, :lol: I loose 2mpg because of my ant.

    So what you do is buy a set of 4 of those spun aluminum wheel covers and get you 2mpg or mor back as you know the slotted wheels are going to add drag too.. ;)
     
  9. jamesbugman

    jamesbugman New Member

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    I read an article a while back about the designing of the new Suburbans. They said that they were removing the mast antenna and going with the embedded one because they gained about a hundredth of a mile (0.01MPG).

    Take it for what it's worth
    James
     
  10. BT Tech

    BT Tech New Member

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    .01 or .0001 percent is probably more like it. I would bet a dirty car would have more of an effect on gas mileage than one that is freshly clean and waxed.

    In other words at the normal speeds that vehicles travel, it is insignificant at best.



    <div class='quotetop'>QUOTE(jamesbugman @ Aug 3 2007, 02:10 PM) [snapback]490038[/snapback]</div>
     
  11. narf

    narf Active Member

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    Glass mounted antennas aren't nearly as effective as a whip antenna. The tend to be fairly directional, and have lower reception because they are blocked by the metal car body. Shark fin antennas are OK for FM , but still have less gain and selectivity than a whip antenna. They are awful for AM reception. In the case of antennas size does matter.

    If you want to learn more than you wanted about the subject, check this web site:Estimation of The Drag of a Roof Mounted Antenna (AU Ford Falcon)
     
  12. viking31

    viking31 Member

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    <div class='quotetop'>QUOTE(Rae Vynn @ Aug 3 2007, 01:13 AM) [snapback]489806[/snapback]</div>
    In many cases it is not a wire, just a thin cord wrapped around the antenna with usually a plastic like compound for attachment. The reason for the spiral cord is to eliminate the annoying whistle like resonance sometimes created by an antenna without the cord.

    With respects to drag, you may be able to quantify the loss of the Prius antenna in perhaps pennies per month.

    A shark fin antenna may look better, but it is even more of a compromise than the OEM Prius antenna. When it comes to FM broadcast reception the closer you can get to 31.5 inches in length, the better the reception of fringe FM stations.

    Rick

    #4 2006