Buying Petrol

Discussion in 'Top Tips & Tricks' started by Phoenix, Jan 13, 2008.

  1. Phoenix

    Phoenix Read Only Funster

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    An extract from Phoenix Travel Club (USA) 2008 newsletter.

    "Only buy or fill up your car, RV or
    whatever in the early morning when the ground
    temperature is at its coolest. Since service stations have
    their storage tanks buried below ground, the colder the
    ground, the denser the gasoline. When it gets warmer the
    gasoline expands, so in the afternoon, or when it warms
    up, your gallon is not exactly a full gallon. A 1-degree
    change in temperature is a big deal."

    Would it save a few bob?:thumb:eek:r not:thumbdown:
    Chris


    Chris
     
  2. oldun

    oldun Read Only Funster

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    As an (ex) engineer, in the good old days, we used to bury our temperature reference probes about 6 ft underground on the understanding that the temperature there varied little from season to season.

    I cannot believe that there is a significant change in the temperature of the stored fuel throughout the day.

    Also the coefficient of expansion of a liquid is minute so the extra mass acquired for a few degrees of temperature fall would also be minute.

    Now with gases things are different
     
  3. ocsid

    ocsid Read Only Funster

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    Lets put it this way as most of us drive diesels:
    If you take on 70 litres and you get 25 miles per gallon, well for every -1 degree C the fuel is dispensed at you will go 556 yards further, and for every -1 degree F just 309 yards.
    Assuming all other aspects related to fuel consumption remain unaffected by the associated temperature change .
    As djchapple points out the subsoil temperature remains pretty constant.
    Big deal there then.
     
    Last edited: Dec 22, 2008
  4. Bulletguy

    Bulletguy Read Only Funster

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    Blimey!

    Twelve months later 'Phoenix' got a reply!!! :BigGrin:
     

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