CLAYCOMO, Mo. --- Ford Motor Co. kicked off production last week of a new, more fuel-efficient version of its popular F-150 pickup line.

It comes at one of the worst times for U.S. truck sales, which have suffered as gas prices have climbed and the housing market has fallen.

Though the automaker is banking on the truck's improved gas mileage to lure back customers --- company officials said fuel cost has jumped to a Top 5 truck buyer concern --- tight credit and increasing worries about economic instability have pulled U.S. auto sales to a 15-year low, with truck sales leading the plunge.

In September, Ford truck sales nose-dived 39 percent as shoppers continued to gravitate toward small fuel-efficient cars.

Little of those fears were evident Oct. 2 as Ford executives cheered the new truck as it came off the line at the Kansas City Assembly Plant, one of two U.S. facilities making the F-150.

"Consumers want this great truck," Joe Hinrichs, the group vice president of global manufacturing and labor affairs, told plant workers and local elected officials. "There's a lot of talk about the truck business. The truck business is strong. The truck business is important to America."

In an interview, Ford officials acknowledged the challenges they face in releasing a new vehicle into the current unstable market. They also said they thought the loyalty of F-Series buyers and the added allure of better fuel economy would help them ride out the current gloom and be ready to take advantage when the economy gets going again.

"The timing is perfect. The truck will solve not only the work needs with superior fuel economy, but it'll provide value that the trucker desires," said Ken Czubay, the vice president of U.S. sales and marketing. "When times are tough, you want to have a product that differentiates yourself from the competition."

Mr. Czubay added that congressional approval of the proposed $700 billion bailout of the financial industry would "have a very important psychological effect" on potential buyers, especially if it encourages lenders to loosen up lending requirements.

"Credit is really the oil that makes the U.S. economy work, and when you throw sand in there it bogs everything down," he said. "Obviously, September was a reflection of that. But we'll get through it."

Ford said the new F-150 has an average 8 percent increase in fuel economy across the entire lineup. The two-wheel-drive F-150 with a 5.4-liter, three-valve V-8 engine averages 14 miles per gallon in the city and 20 mpg on the highway, compared with 13 mpg in the city and 17 mpg on the highway for the 2008 model.

A Superior Fuel Economy version for 2009 increases the mileage to 15 mpg in the city and 21 mpg on the highway. That matches the averages of the most fuel-efficient versions of General Motors Corp.'s two-wheel-drive 2009 Chevrolet Silverado and GMC Sierra.

The SFE package will be a no-cost option on XLT SuperCrew pickups with the chrome package. It will cost $1,095 when ordered on XL SuperCrew pickups with the dÃcor package.

The improved fuel economy comes from a combination of lighter steel construction that reduces the body weight by 100 pounds, better aerodynamics to reduce drag, a new six-speed transmission, over-valve fuel injection and an automatic fuel shutoff triggered when the driver releases the gas pedal.