Volume Corrected Gas Pumps

[95metro]

Sometimes while filling up I have noticed this sticker on the gas pump I'm using:

this register has been volume corrected to 15 degrees celsius

Curiousity led to a Google search and I found this article. Perhaps this doesn't affect you, my American friends, and it may not have a huge impact on overall fuel economy (though it could account for some of my winter FE loss), but it may be worth considering overall.

http://www.cbc.ca/consumers/market/f...ice/index.html

[zpiloto]

I'll have to look and see if they have that sticker down here. I've got to fill up this weekend. It suppose to 95. Throw that in with the accurracy of the pump shut off and it can really make a difference in FE from tank to tank.

[Gary Palmer]

95 Metro:

When I read this article, I am a bit confused. If the gas pumped is temperature corrected to 15 degree's, but the actual temperature is colder, then the amount of energy in a certain volume would be higher, wouldn't it? I really am baffled by the guy's claim that you aren't buying energy. If your not buying energy, then what in the world are you buying it for. Sounds like some pretty goofy logic.

[95metro]

I don't know, I don't completely understand the logistics of it, but it certainly does seem like you are buying energy by volume. It also seems as if you would be buying more of it in winter and less in summer.

You expend more energy in winter to go the same distance as in summer time - our FE charts prove that over and over again. If something contracts as it gets colder then there is more mass per volume so that would seem to say that there is more potential energy in a winter tank, but it is completely nullified by the mass of cold air swallowed by your engine - more energy needed to create propulsion and heat when the weather is cold.

But if the pump is volume corrected way above the actual outdoor temperature then the reading it is giving is higher than what you actually put in your tank...maybe. Perhaps the energy/volume equals out in the end.

I'm too tired to think about it at the moment...

[philmcneal]

they say if you buy your gas in the morning, (where its cold) and then pump it into your gas tank. When by day its all nice and sunny the gas inside your tank should in theory expand therefore giving you more gas for the same buck.

But by correcting that volume that advantage is not as great as they say it would be. I guess its corrected due to emissions reasons as well if in case those that has a gas tank that does not absorb fuel vapors (they go in the atmosphere) .

So if its 15 degrees C (like my gas pumps) then we have to see temps as high as 30 degress C in order to milk more gasoline than what we have in our tanks already.