With mounting pressure on Indian manufacturers to meet future fuel economy and emissions mandates-including the recently passed Corporate Average Fuel Consumption (CAFC) standards for light-duty vehicles-many are evaluating new technologies. However, to provide an economically sustainable solution, these technologies must increase efficiency without increasing cost.One promising solution to meet both current, and future, standards is the opposed-piston engine. Widely used in the early 20th century for on-road applications, use of the opposed-piston engine waseventually discontinued due to challenges with emissions and oil control. But advancements in computer-aided engineering tools, combined with state-of-the-art engineering practices, has enabled Achates Power to develop a modern opposed-piston diesel engine architecture that is clean, significantly more fuel efficient and less expensive to manufacture than today's four-stroke engines.In addition to a short explanation of the opposed-piston engine and its inherent efficiency benefits, this technical paper will provide detailed performance and emissions results of a multi-cylinder Achates Power opposed-piston engine configured to meet commercial truck requirements. These results, which will be presented for the first time in India, demonstrate the engine's ability to: Substantially improve fuel economy over the best diesels in the same classComply with U.S. 2010/Euro 6 emissions standardsThis paper also provides a detailed overview of the opposed-piston multi-cylinder test engine's indicated thermal efficiency, friction and pumping losses.