While pickup trucks account for just 20 percent of U.S. vehicle sales, six of the ten biggest gas-guzzlers at the pump are pickups, according to a report from the Union of Concerned Scientists. The study, which looked at the 50 most popular trucks and cars, found that Dodge Ram owners paid the most for fuel -- an average $1,468 a year. That's $250 more than the average light-truck driver and almost $13,000 in total fuel costs over the life of the vehicle."Pickup drivers are disproportionately burdened at the gas pump," said USC senior analyst David Friedman, who wrote the study. USC is a group that lobbies for "practical environmental solutions."Friedman said off-the-shelf technology could raise the gasoline mileage of light trucks by 30 percent, saving the average driver more than $300 a year in gasoline costs. However, U.S. automakers have warned that significantly raising fuel standards would be costly and may result in less safe vehicles that are made from lighter-weight materials.The report's fuel costs are based on a gasoline cost of $1.40 a gallon and a vehicle driven 15,000 miles a year."Automakers have fallen asleep at the wheel on fuel economy," said Friedman. "It's time for manufacturers to give pickup drivers the gas mileage performance they want and deserve."A national survey released by the Mellman Group found that 76 percent of pickup drivers support a boost in vehicle fuel standards. Another 87 percent said they would be willing pay $500 more for a new, higher-mileage, pickup truck if they could save $2,000 in gasoline costs over the life of the truck.Of the 600 pickup drivers surveyed, 57 percent lived in small towns and rural areas.Under a broad energy bill that passed the U.S. Senate, pickups would be exempt from any future increases in federal vehicle fuel standards, but a related energy bill passed by the House of representatives contained no such provision.When lawmakers return next week from the summer recess, Senate and House negotiators will resume hammering out differences in their energy bills. They will also tackle whether to require a small boost in overall vehicle mileage requirements in the final bill.