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a source of error in MPG calculations - hot gas!

Discussion in 'Gen 2 Prius Fuel Economy' started by flyingfysh, Sep 4, 2006.

  1. flyingfysh

    flyingfysh New Member

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    There is an interesting story in http://www.consumerwatchdog.org/energy/nw/...for+big+oil%3A+

    Basically, when the weather is hot, you don't get as much gasoline as you think you are, because gasoline expands in hotter weather. Pumps in the US do not compensate for gasoline temperature as they do in Canada. So if your mileage is worse in really hot weather, there could be a good reason.
     
    #1 flyingfysh, Sep 4, 2006
  2. Tempus

    Tempus Senior Member

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    Most gasoline that is stored in underground tanks is at pretty much the same temperature year round.
     
    #2 Tempus, Sep 4, 2006
  3. Bill Merchant

    Bill Merchant absit invidia

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    <div class='quotetop'>QUOTE(Tempus @ Sep 4 2006, 07:28 PM) [snapback]314315[/snapback]</div>
    Or so the oil retailers would have you believe. The problem is we buy gallons, not energy. My natural gas bill shows the cubic-feet used from the meter and an energy adjustment factor. We should be so lucky at the gas station!

    Did you read the article? When the oil retailers were losing money with cold gasoline in Canada, they got temperature compensating pumps mandated. Where it's warmer, it wouldn't be "cost effective." How warm does gas get in a tanker? How fast does it cool in the station tank?
     
    #3 Bill Merchant, Sep 5, 2006
  4. jbarnhart

    jbarnhart New Member

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    That's a facinating article. One thought that bothers me... if we were to compensate for the hot fuel issue, wouldn't the price of gas just rise to accomodate it? Since the price of fuel is market-based, it seems that the price would respond if the volume of gas were adjested.

    I think a far bigger problem is enforcement of weights and measures. In California, the state government pretty much did away with enforcement of accuracy in gas pumps. As a result, my cars all hold up to 10% more gas then they used to!
     
    #4 jbarnhart, Sep 5, 2006
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