The average price of gas down six cents over the past two weeks to $2.20 a gallon: Analyst Trilby Lundberg with the Lundberg Survey, who says a seasonal weakness in demand is one reason behind the decline and U.S. refiners are increasing supplies now that autumn maintenance projects are wrapping up. San Diego with the highest price at $2.73 a gallon. The low in Tulsa at $1.78 a gallon. Lisa Lacerra, FOX News.