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Does a passenger greatly reduce overall MPG's?

Discussion in 'Gen 2 Prius Fuel Economy' started by Soylent, Aug 30, 2006.

  1. Soylent

    Soylent The v isn't a station wagon! It's just big boned

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    Does a passenger greatly reduce overall MPG's? Obviously there will be a difference between a child and an adult, but I would assume that having a passenger greatly reduced the MPG, since the car has to haul more weight. Has anyone tested the same run with a passenger, and then without a passenger?
     
  2. TheForce

    TheForce Stop War! Lets Rave! Make Love!

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    I have and it does reduce it by a few MPG. Not much but I can see a difference.
     
  3. efusco

    efusco Moderator Emeritus
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    Guess it depends upon your definition of 'greatly'. But overall it doesn't make much impact.

    Using Wayne Brown's THSII simulator:
    80 degrees, Driver + cargo weight 250 lbs and a few other things of lesser significance but balanced on all other measures.

    No Passenger @ 35mph: 87.5 mpg
    185 lb passenger @ 35mph: 85.8 mpg

    No px @ 55mph: 62.6 mpg
    185lb px @ 55mph: 61.6 mpg

    No px @ 75mph: 47.7 mpg
    185 lb px @75 mph: 47.1 mpg

    These are some ideal conditions number so don't freak if they don't seem realistic, but they give a frame for comparison.
     
  4. eagle33199

    eagle33199 Platinum Member

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    If you ask me, the passenger effects the MPG by more than just their weight would warrent... It's the constant talking that does it, distracting you from your driving so you don't get optimal MPG's.

    My little sis was just in town visiting this past weekend. when i picked her up at the airport, i was sitting at 54 MPG. when i dropped her off, it had dropped down to 48 MPG.
     
  5. Soylent

    Soylent The v isn't a station wagon! It's just big boned

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    <div class='quotetop'>QUOTE(eagle33199 @ Aug 30 2006, 10:42 AM) [snapback]311566[/snapback]</div>
    :lol: That's funny, you're right about that! And not to mention you'll be showing off, too.
     
  6. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    additional passengers do make a difference. i have tracked a certain trip made alone (170 lbs) and with 3 others in the car est weight (140, 160, and 120. only the 160 is for sure, the other two are females and...well, lets not get into that) and the difference ranges as high as 4 mpg.

    i think some of the difference can be extra wind drag for windows that would not normally be open if i were alone in the car. with vents up front, i can usually find a setting that is comfortable (and quieter) than cracking a window. with people in the back, someone usually opens a window.

    i will say that in case of A?C usage, the extra weight puts a much bigger hit on the MPG's than normal
     
  7. nerfer

    nerfer A young senior member

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    <div class='quotetop'>QUOTE(Soylent @ Aug 30 2006, 08:30 AM) [snapback]311540[/snapback]</div>
    The more important thing is people miles per gallon, not vehicle miles. If you didn't have the person in your car, would they be driving an additional vehicle, one that gets maybe 20 mpg, sucking up fuel resources, adding to gridlock and polluting the air?
    Even if two Prii owners carpool, then two people go 50 mpg = 100 people-miles per gallon. If they drive separately, but each gets 55 mpg, then it's just 55 people-miles per gallon, and almost twice as much gas is used.
     
  8. qbee42

    qbee42 My other car is a boat

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    <div class='quotetop'>QUOTE(Soylent @ Aug 30 2006, 09:30 AM) [snapback]311540[/snapback]</div>
    Depends on their size and how you carry them. Inside causes the smallest change. On the roof I find you do better if you orient your passenger the long way - less drag. Head first reduces nose drag, but this varies widely by individual. Dragging behind has the least wind drag for an external passenger, but then you get all of the friction. The good news is that the friction drops off over a fairly short distance. :blink:

    Tom
     
  9. adgo82

    adgo82 New Member

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    When I pick up slugs I see about a 2mpg drop, which makes me mad :p I am trying to reach 60mpg hehe I was on 58mpg and now I am down to 56mpg. Oh well :D
     
  10. Beryl Octet

    Beryl Octet New Member

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    <div class='quotetop'>QUOTE(Soylent @ Aug 30 2006, 09:30 AM) [snapback]311540[/snapback]</div>
    It probably hurts a small amount, but my passenger gets mad when I make them take their own car when we are going out to eat or shop.
     
  11. aaf709

    aaf709 Ravenpaw of ThunderClan

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    It depends on who's the passenger. If it's my wife alone, there's not too much, but there's a couple of friends of mine that can drag it down (although not that much if all freeway). :)
     
  12. hyo silver

    hyo silver Awaaaaay

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    I agree. Depends on the passenger. (And I'm not talking about their waistlines.) My Dad says "Floor it . Let's see what she'll do." My wife says "Am I ever glad we didn't buy a sports car." :)
     
  13. wilco

    wilco New Member

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    I agree that it depends on the passenger. I seldom use the a/c, my wife always turns it on. She seems to like using the heat in the winter too... imagine that!
     
  14. nerfer

    nerfer A young senior member

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    <div class='quotetop'>QUOTE(Beryl Octet @ Aug 30 2006, 12:25 PM) [snapback]311660[/snapback]</div>
    I hope that's humor :unsure: ...the important thing is to reduce total gas used, not the bragging rights on MPG by making other vehicles pick up your slack (like passengers or cargo left behind) or driving a longer distance for better MPG but also using more gas.
     
  15. badaka

    badaka New Member

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    If they are over 257 pounds make them get in the rear passenger seat ... you'll gain @ .7 mpg as opposed to up front. Trust me.
     
  16. galaxee

    galaxee mostly benevolent

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    mainly i lose mpg by actually having to use the a/c when i carry passengers...
     
  17. jburns

    jburns Senior Senior Member

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    It's possible.

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