Wall Street Journal: Hybrids and electric cars are generating the buzz this week at Detroit’s North American International Auto Show. But thanks to new technology, the century-old internal-combustion engine appears poised to make a significant leap in fuel efficiency. While car makers are showcasing gas-electric hybrids, plug-in hybrids and concept cars powered by fuel-cell batteries, they also are rolling out vehicles with advanced gasoline engines that rely on a technology known as direct fuel …