While there's much hype in the auto industry about the future of electric and battery-powered cars, Chrysler is rolling out a heavy-duty pickup truck that runs on compressed natural gas, betting that Americans can be convinced to start adopting the vehicle by touting its fuel as clean and homegrown. Later this year, the company will start selling a natural gas version of its Ram 1500 pickup truck, joining Honda as the second automaker to offer a compressed natural gas (or CNG) vehicle to the American public.