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...Full Story