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heavy weight drivers effecting mpg?

Discussion in 'Gen 2 Prius Main Forum' started by jordan122342, Jan 20, 2008.

  1. jordan122342

    jordan122342 New Member

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    In 2 weeks I will have my very own black 08 #5 prius and I am so stoked, unfortunetly I am one of the many americans struggling with obesity. I am working on it and have lost 42 pounds hallelujah! And still going! But my concern is that with me and my wife in the car, the combined weight of the 2 of us totals to around 450 pounds. Now is this going to very heavily screw up my mpg number? Like I said I'm actively working on it, and am loosing a little more each week, but I'm really concerned that I'm going to get the same mpg as I did with my piece of sh*t jeep grand cherokee which is around 16mpg. Does anyone here carry or cart around about that much weight in their prius on a usual basis and see a significant effect on your mpg? Thanks!
     
  2. Rae Vynn

    Rae Vynn Artist In Residence

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    Um, no. :)

    When I was carpooling to work, the combined weight of me and my coworker was well over 500 lbs, and I was still getting well over 50 MPG.

    I get less now because it's cold, and I'm making short trips, even though the weight factor is similar or less (no longer carpooling).

    Driving habits, atmospheric conditions, and trip length are the main factors, in my opinion.
     
  3. V8Cobrakid

    V8Cobrakid Green Handyman

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    i'm curious to strip the car down to see how light i can get it... i weight 180lbs. I figured i could at least find 100lbs worth of crap to displace... trim panels and such.. lol

    maybe i should wait till i get lighter rims.. my 17's are monsters... so after i get new rims.. it would be cool to lighten the car for a test.

    I've carried near 1000lbs of lumber and concrete and my mpg was about 35 to 40... but i normally got around mid 40's.. so it's not bad.. i have a lead food.. even carrying lumber and concrete.
     
  4. Sp33dy_gr33n

    Sp33dy_gr33n New Member

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    The velocity in which you are traveling will have more of an effect on MPG than mass does. If you look at the drag equation, velocity is squared...this is a huge effect. To get better mileage, slow down.
     
  5. V8Cobrakid

    V8Cobrakid Green Handyman

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    aww.. gradual acceleration? but that's soo slow.... hehe
     
  6. GeekEV

    GeekEV Member

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    I was 280 there for a while (now 250), AND I have a lead foot, but I still get 40 - 42 MPG.
     
  7. Rxmxsh

    Rxmxsh Member

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    Just wanted to pop in and say - Good for you that you're losing weight. A lot of people don't care about their weight or health. I used to be 240. I'm at 150 now, and hitting the gym hard to get to about 170 w/muscle. My body fat used be over 34%, and now I'm down to 19%.

    It's doable! Just stick in there!
     
  8. galaxee

    galaxee mostly benevolent

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    depends more on your commute... when i was driving the prius i with my 3 mile commute i got about 42-43 mpg driving it nicely. i'm not a big girl but i've got solid muscle mass.

    now, DH drives it to the next town and back every day ~70 miles r/t. gets it nice and warmed up but he drives fast and brakes hard. he gets 44 mpg and is about 40 lbs heavier than i am.

    [shrug]

    i've TRIED to get bad mpg and i can't get it under 40 mpg without a tank of bad fuel. no need to worry :p

    and good luck with the weight loss! that's a truly great thing to do for yourself and your family.
     
  9. jordan122342

    jordan122342 New Member

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    thanks for the encouragement mate, yeah i am far above what my medically determined ideal weight is, i have 49% body fat (or at least it was 42 pounds ago!), meaning quite literally half of my body is fat. its embarrassing to say the least. but a thought had come into my head, to apply to be on the biggest loser. i think that would be so awesome, reppin my prius buddies! and if i won the competition and got the $250,000 i would buy 10 prius' and give them to specific members of my family. :)
     
  10. John in LB

    John in LB Life is good

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    The above is partly true.

    The weight of the car will be the key factor for energy consumption when speeding up, slowing down, going up or down hills. Especially at speeds where wind velocity are not significant / turbulent (e.g., around town, starting off from a street light). In these scenarios, how fast you are going (and the related drag effect) are negligible.

    At highway cruising speeds, the car's wind resistance is the key factor for energy consumption - weight has a negligible effect (except if you are also going up a hill or trying to speed up, then both factors play a part).

    That's why you want both attributes in your car... you want it light AND you want it aerodynamically efficient. The Prius attempts to do both of these things.
     
  11. Doc Willie

    Doc Willie Shuttlecraft Commander

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    Hmmm... losing 20 lbs before the HybridFest fuel economy challenge . . . There's a goal for me.
     
  12. Codyroo

    Codyroo Senior Member

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    I seem to recall reading something (a few years ago) that said you could get improved mileage by removing items that add weight (golf clubs etc) that don't NEED to be in the car. I believe that same article said that for every 50 lbs, you could affect your gas mileage by 1 mpg. Now, take into account that this is (likely) a very simplistic arguement/illustration.

    Speed and driving make a bigger difference than your weight.

    In my Integra, I used to drive 70 mph and I got about 32 mpg. When I slowed down to 55 mph, my mileage shot up to 38-39 mpg. When I started carpooling with a coworker (guessing she was about 135 lbs) it dropped by about 1.5 mpg (but since I only had to drive half the time, I only had to fill up every other week....heh!).

    So, carpooling dropped it off by 1.5 mpg. Slowing down raised it by 6.5 mpg. Speed kills! (if I had merely slowed down to 60 mph (55 mph bites), I'd probably be averaging 37 mpg instead of 38.5 mpg.
     
  13. ny biker

    ny biker Member

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    Hey Jordan, congrats on the 42 lbs and best of luck with your continuing efforts!
     
  14. JimboK

    JimboK One owner, low mileage

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    The Prius MPG Simulator suggests that reducing the load by 50 pounds improves fuel economy by less than 1/2 percent. This assumes steady speeds on level terrain. Frequent acceleration/deceleration or hill climbing probably magnifies it some, but I'm sure it's still quite low.

    But keep up with the great work!
     
  15. abq sfr

    abq sfr New Member

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    I had 5 large people in my Prius over Christmas... plus we all ate a lot! Let's see, must have been over 1000 lbs of meat in there. Besides bottoming out on speed bumps (even with 40/38 TP), I don't think there was any other noticeable effect. Since the car rides lower to the ground, maybe it will INCREASE your FE. Takes more energy to get it going, but inertia will keep it going longer?
     
  16. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

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    ok... i be lone dissenter i guess.

    ya, weight will affect your mileage. not a lot, few mpg's but i do see a difference since i am either alone or have a car full.

    but that is just another good reason to lose the weight... its not doing you or your family any good at all (unless you are a sumo wrestler or anchor on a tug of war team)