“In the summer time fuel gets hot and as the fuel gets hot the volume expands, but the energy does not,” says a new report from NPR. The basic idea is that while the volume of fuel expands and contracts, the amount of potential energy within the gas stays the same. A gallon of gas at 80 degrees won’t push a car as far as a gallon of gas at 60 degrees.

The difference is about 1%, enough to force wholesalers to sell “temperature adjusted” gas. If you gas is hot, the gas station owners get more of it for the same price. Not so with a gas pump. You pay the same for gas no matter what temperature it is.

NPR says the House of Representatives estimate you’re losing $2 billion dollars a year to expanded gas. Fuel companies say the winter months even it out. NPR also points out that “summer” gas (a different blend required by the EPA) actually has more energy per gallon…about 1-2% more.

Nevertheless, there’s a raging debate going on in several southern states about whether the nations gas station pumps should be retrofitted to adjust for temperature changes. If you’re lucky enough to live in Hawaii this doesn’t concern you; Hawaii is the only state to adjust for warmer gas.

Heat Throws Off Gas Pumps, and Motorists Pay [NPR]
(Photo: moorsteen)

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