American vehicles are piling on the pounds

Automakers work on ways to slim down as gas price tops $3 a gallon

Ballet dancers and professional jockeys are not the only ones who worry about weight. U.S. carmakers worry about it too, and with good reason: Even as the price of gasoline has crept higher in recent years, their cars are piling on the pounds.

The average weight of a U.S.-made vehicle has increased by 500 pounds over the last 10 years to 4,142 pounds, according to the latest data from the Environmental Protection Agency. The average weight of current vehicles is now the heaviest since the EPA began measuring weight in 1975.