Abstract
In general, diesel engines (DE) have an advantage in thermal efficiency by comparison with gasoline engines. In recent years, DE is getting cleaner with NOx aftertreatment devices such as LNT and SCR in addition to common rails and Diesel Particulate Filter. On the other hand, due to the increase of fuel efficiency-oriented consumers worldwide, further improvement of fuel consumption is expected to DE. Under the circumstance, the authors developed and introduced New Generation Clean DE into the Japanese market as SUV segment. A serial sequential 2-stage turbocharger system was employed to a turbocharging technology in support of low compression ratio to achieve ideal combustion. This enabled the engine to achieve good driving pleasure, high fuel efficiency, and compliance with regulations without NOx aftertreatments.
