Fuel expands in heat, but special pumps could compensate for temperature swings
THE SAN FRANCISCO CHRONICLE
When you buy a gallon of gas at the service station, you don’t always put the same amount of energy in your tank.
Gasoline, like other liquids, expands in high temperatures. Although gas pumps always dispense the same amount, the fuel is less dense when it’s warm. That means you spend a little bit more to get the same amount of power for you car.
Consumer advocates say drivers are getting short-changed, particularly in warm-weather states such as California.
“This is a system that is totally rigged to misrepresent how much gas you’re getting,” said Jamie Court, president of the Foundation for Taxpayer and Consumer Rights.
How much does this cost drivers? A study by the Kansas City Star newspaper, which brought the issue to light, estimated that Californians would save about $450 million if the state’s gasoline pumps adjusted for temperature.
Such pumps exist, just not here. Canada uses temperature-adjusting gas pumps, as does Hawaii.
Consumer groups want those pumps installed in California and across the country. Indeed, Gilbarco Veeder-Root, a North Carolina company that makes temperature-adjusting gas pumps, recently won approval from California regulators to sell its equipment here.
But the company dropped its plans after being pressured by oil and gasoline businesses that don’t want the pumps sold in California, the Star reported, citing unnamed sources.
A Gilbarco representative could not be reached Monday.
While the report couldn’t be confirmed that oil company pressure prompted Gilbarco to change its plan, there’s no question that many in the industry don’t want the pumps installed. Dan Gilligan, president of the Petroleum Marketers Association of America, said converting all the country’s pumps would cost $2 billion to $3 billion. And introducing them piecemeal, a few at a time, would confuse consumers, he said.
Gilligan said his group didn’t pressure Gilbarco to drop its plans for California. But it didn’t like those plans, and it let Gilbarco know.
“We told them that what they did in California was not a good idea,” Gilligan said. “We think it would be a very bad circumstance for marketers to choose to compensate for temperature.”
The issue has already provoked lawsuits against some of the country’s largest oil and gas companies, Chevron, ConocoPhillips, Tesoro and Valero.
The dispute involves physics and oil-industry arcana. Because gasoline expands and contracts based on temperature, the industry uses a standard temperature — 60 degrees Fahrenheit — as part of its definition of a gallon. To the industry, a gallon of gasoline is the amount of fuel that occupies 231 cubic inches at 60 degrees.
But at 75 degrees, the same amount of fuel occupies 233.4 cubic inches, according to one of the lawsuits. At 90 degrees, the gas expands to 235.8 cubic inches.
The standard gasoline pump doesn’t take this into account. So when the fuel gets warm, the gallon you buy has less energy content than it would at 60 degrees. The reverse happens when the gas is cold — you get more energy content than you would at the standard temperature.
Although air temperatures swing widely, during the day and during the year, gas stations store their fuel in tanks below ground, where the temperature is more constant. So it’s difficult to know exactly how much the temperature of the fuel changes.
Gilligan said that over the course of a year, the temperature changes in fuel should cancel themselves out, forcing drivers to pay a bit more in warm weather and a bit less in cold.
“In the greatest part of America, consumers are made whole over the course of the year,” he said. “They lose a little (energy) content in the summer and gain it in the winter.”
But that might not be true in perpetually warm places such as Southern California or the Southwest.
“I’m really not sure what the numbers would be in California,” Gilligan said.
Consumer advocate Court on Monday called for the California Attorney General to investigate whether any undue pressure had been placed on Gilbarco not to sell its pumps in the state. A spokesman for the attorney general’s office said the office will look into the matter.
In addition, a spokeswoman for Sen. Barbara Boxer said the senator will ask Gilbarco’s chief executive officer why the company decided against selling its pumps here.
The California Democrat also held open the possibility of asking the Federal Trade Commission to investigate.
The problem: Gasoline expands as it gets warmer, becoming less dense. But most American gas pumps dispense the same volume — 231 cubic inches per gallon — and don’t compensate for temperature. That means a gallon of hot gasoline has less energy than a gallon of colder gas.
The cost: One study estimated that Californians would save $450 million if gas pumps compensated for temperature. Consumers across the country would save $1.7 billion.
Sources: Chronicle research, Kansas City Star