Combustion engines in cars may be on their way out, but experts agree it will take a few decades before electric-powered vehicles become dominant. Meanwhile, the existing gas and diesel engines can be made more efficient and less polluting. With a $9 million grant from the U.S. Department of Energy, a U.S.-based company is using an old technological concept to build a power-train that is 50% more fuel-efficient and just as powerful as conventional engines, as VOA’s George Putic reports.