www.kansascity.com/mld/kansascity/15370193.htm

Has anyone noticed this? I first saw this in Yesterday's (08-28-06) New York Times.

Previously everything I'd read on this topic claimed that US fuel distribution is temperature compensated. Now it appears not? Whats up with this?

Fuel does expand when hot, however most fuel tanks are underground and maintain a fairly cool an even temp. Also the difference in volume between 60 and 90 degrees is very small (1.7%). I doubt you can buy 90 degee gas many places. On a hundred degree day with the AC off my upstairs might hit 85-90 but the basement is much cooler, perhaps 75. How many above ground storage tanks have you seen? I'd be surprized if underground storage varied in temp by more than 15 degrees year round.

Yeah, all the Ric Romero articles about saving gas mention this.

What about when it gets cold and gasoline increases in density? Should we pay more for it then since we are getting more? I think it all comes out in the wash. I remember reading years ago in one of those Shell handouts they used to have that you should always buy your gas at night since you are getting a slight bit more.

Does anyone know at what temperature gasoline reaches it's maximum density?

Oil like solid minerals such as concrete do expand with rising temperatures but this article brings this to the point of paranoia with your gas station. It's assuming the the temperature in an underground tanks can reach high temperatures and thus expand greatly, costing you personally lots of money every year.

Well for one a protected underground tank for gas doesn't greatly cary temperature throughout the year. Even in a place like New England with cold winters and recent hot summers doesn't affect the temperature more than a few feet underground. Think of the partially buried homes some people use, they save people money on heating beacause they are partially underground which acts as an insulator. And during the summer, the buried homes are cooler inside because they are protected from the sun. A gas tank at least say 5-6 feet under our feet would not see that great change in temp around the year. The only time to worry is when they add more gas perhaps, the temperature from the truck stored gas being less protected.

The whole report does point out that a lot of gas stations cycle through new gas quite often, so the gas dont stay there long enough to "cool" down to underground (fairly constant) temperature. It also points out that regulation requires better storage tank and thus better insulator, so again, the gas doesnt cool quite as fast. So if the temprature of the gas from the trucks are hotter than 60deg, then it is still higher than normal when you pump it, on average.

For most of us, the difference is prob in the noise because the cost is distributed over millions of pockets, but the gas company gets to add all that and see it in their bottom line. This gain is real (and not insignificant) for them, as noted in the article that they implemented all type of temperature compensation in "cold" Canada, and in their vendors, but vehemently fight against implementation when they are the vendor. Seems like double standard in their favor to me.

Well, at least in New York, we have cold winters to make up for the hot summers. People in Florida are screwed year-round. (Thanks for G.W.! Have a nice day!)

Would-be hypermiler