Consumers are having to dig deeper into their pockets to pay for gasoline, so they're not buying as much elsewhere. The Commerce Department says retail sales weakened more than expected last month. The decline of one-point-one percent is the biggest in 16 months, much of that because of falling car sales. The drop virtually erases strong gains seen in May. Excluding the automobile sales component, sales were down two-tenths. Economists believe rising energy costs are part of the reason. A more temporary factor cited is moderate weather in some parts of the country, which hurt demand for summer items.