General Motors Corp.'s first hybrid gas-and-electric-powered pickup trucks will be built at the company's Fort Wayne, IN plant. Production of hybrid Chevrolet Silverado and GMC Sierra models is to begin this year, with the vehicles first being offered to GM's fleet and commercial clients. GM says the new electric motor systems will be capable of boosting gas mileage on the pickups by up to 12% from their current average of 21 mpg on the highway.