The new transmission for Ford Motor Co.'s 2011 Super Duty pickup will be a significant improvement over the current five-speed automatic in the areas of performance and fuel economy, a Ford engineer said.

Dick Boerema, Ford engineering manager, said during a Web conference that the vehicle will be a "clean sheet" because it's not an evolution of the current product. He added that the vehicle will be significantly improved over the current version.

Set to go on sale next spring, the vehicle is also notable in that it will be Ford's first in-house designed diesel V-8 truck engine.

The truck will have a new body and a new six-speed automatic transmission. Fuel economy for the truck will be "very competitive," Boerema added.

Although fuel economy estimates are not required on the window sticker because heavy-duty pickup trucks are in a different weight class and do not have to conform to passenger-car standards, Ford will announce more details on the fuel economy of the truck as it gets closer to launch.

Ford's new transmission uses a one-piece case that saves 25 pounds compared with the GM Allison transmission used in heavy-duty versions of the Chevrolet Silverado and GMC Sierra. The GM Allison transmission uses a three-piece case.