Engine downsizing using supercharging is progressing to cope with tightening global
environmental regulations. In addition, further improvement in fuel consumption is expected with
such applications as ultra-high EGR, Miller cycle, and lean combustion. Mitsubishi Heavy
Industries, Ltd. (MHI) has developed a two-stage electric turbocharging system to balance better
drivability and improved fuel consumption by increasing the turbocharging pressure and
improving the transient response.
