Supercharger Demonstrates Improved Engine Torque and Emissions: A mechanically driven supercharger had been known to increase torque at low speeds; however, difficulties in controlling EGR and relatively high parasitic power loss prevented this technology from being developed for production diesel engine application. Engineers at the Isuzu Advanced Engineering Center revisited the mechanical supercharging technology and investigated the potential of applying a supercharger to a heavy-duty diesel engine. A 3-liter, inline four-cylinder, turbocharged DI diesel engine designed to meet Japan's 2005 emissions standard was equipped with a supercharger, and the test results were evaluated and compared with those of the turbocharged engine.