It's already painful filling up at the pump these days. But the pain only gets worse during summer months because hot gasoline doesn't have as much energy as it does in more mild temperatures.
Industry officials and regulators struck a deal long ago to classify a gallon of gasoline as 231 cubic inches at 60 degrees. But when temperatures heat up, gasoline expands, just like most liquids, providing less energy per gallon.
Consumer groups say drivers could lose between 3 and 9 cents for every gallon they pump. That means if they fill up their 20-gallon tank with hot gasoline, they will be shortchanged about $1.50.
The losses can add up. Congress estimates that this summer alone, consumers will lose as much as to $1.5 billion from gasoline expansion.
Public interest organizations say consumers are getting a bad deal.
"It's not fair when motorists are pulling up to the gas station and paying for gas they're not actually receiving," said Tyson Slocum of the public interest watchdog organization Public Citizen.
Now some say it's time for the oil industry to pay for consumers' losses. There are now more than 20 lawsuits from California to Delaware suing the oil industry. The lawsuits ask for companies to install devices that take into account the temperature of gasoline when charging customers. Canada, whose cool temperatures favor consumers, already uses such devices.
"What we're alleging is that the consumers are getting less value per gallon for the gasoline that they're buying," said attorney George Barton. "The equipment is readily available to fix these problems."
But the fix won't come cheaply. NATSO, a national trade association representing travel plaza and truckstop owners and operators, says it would cost locations with modern pumps $2,000 to $7,000 to outfit a pump with the technology.
"Before costly solutions are forced on consumers and retailers, it's imperative to confirm whether the problem is real, how widespread it is, and whether the costs of implementing any solution will be offset by a real and measurable economic benefit, if any, to the consumer," said Jay McKeeman, the vice president of government relations and communications for the California Independent Oil Marketers Association, in a NATSO press release.
The oil industry thinks the prices are fair. Industry officials point out in winter temperatures, consumers use cool gasoline that provides more energy per gallon than usual.
Still, opponents say all is not equal. Consumers drive more in the summer when both temperatures and gas prices are high.
With the National Conference on Weights and Measures weighing in on the controversy next week, the issue promises to stay hot.