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The benefit of the wind

Discussion in 'Gen 3 Prius Fuel Economy' started by DumbMike, Apr 22, 2014.

  1. DumbMike

    DumbMike Active Member

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    I know the wind can make a difference, but not this much.

    While driving from Los Angeles to Las Vegas, I stopped in Victorville to gas up. I noticed that it was very windy (sorry, but I don't know the MPH of the wind). Started driving north on I-15, set my cruise control to 80MPH, and after a few minutes, I notice I'm getting around 55MPG. Normally, I get around 40MPG (or even less if I'm driving faster) doing this drive. What makes this weird is that the normal wind direction is to the south, plus it is very slightly uphill. When I stopped in Baker, I noticed that the wind had dropped significantly, and from Baker to Las Vegas got my normal MPG.

    But a 15MPG benefit solely because of the wind? That's great in my book. Luckily the wind wasn't blowing against me on my return trip, otherwise MPG in the low-30's would be pretty bad.

    Mike
     
  2. dorunron

    dorunron Senior Member

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    Don't discount the wind. It does make a difference. Speed also makes a difference. Changes in altitude can also affect it. Lots of variables when it comes to MPG on various trips.

    Ron
     
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  3. JC91006

    JC91006 Senior Member

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    That stretch from the cajon pass downward to Victorville will get you 99mpg going 70mph. It's mostly all downhill from there to Barstow.
     
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  4. miscrms

    miscrms Plug Envious Member

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    Its seems possible. At 80mph about 67% of your fuel burned is spent overcoming air resistance. An increase from 40mpg to 55mpg is about a 27% reduction in fuel consumption.
     
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  5. miscrms

    miscrms Plug Envious Member

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    Yeah, Victorville to Baker looks like a net loss of ~1800 ft in elevation, which would contribute significantly.
     
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  6. JC91006

    JC91006 Senior Member

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    This is more of a down hill factor, not so much a wind factor.

    SM-N900P ?
     
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  7. Codyroo

    Codyroo Senior Member

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    Wind plays a major part in MPG's, don't discount or underestimate it. When crossing the San Mateo bridge in the morning, with no wind, I can expect ~65 mpg when traveling around 58 mph. If there is a strong crosswind, it will drop to ~55 - 60 mpg. If there is a strong headwind, I will get 45-50 mpg. Slowing down to 53 mph or so will improve it to the 50-55 mpg range with a headwind. I don't know how strong the wind is, but assume 20 mph = strong.
     
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  8. DumbMike

    DumbMike Active Member

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    I don't think it's much of an elevation difference, depending on which site you use, it's about 200-400 feet difference, and that's spread out over 100 miles. So, I think in this situation, the wind was playing more of a part in the increase in MPG. But I agree that the elevation difference can also be a major factor. The Cajon Pass causes some different issues as it is mainly uphill going from where the 15 and 215 meet to Victorville. But, I started my calculation at Victorville, so I was already past the Cajon Pass.

    My evaluation is simply from comparing prior experiences to this last one. Now I gotta figure out how to keep the wind at my back going both directions.

    Thanks everybody for the comments.

    Mike