Diesel engines are used as a power source for various industrial machines because they have greater fuel versatility and are more fuel efficient than other internal combustion engines. Meanwhile, emission regulations have been tightened year after year. In the United States, the EPA Interim Tier 4 emission regulations for engines with a rated output of 56 kW or more to less than 75 kW become effective in 2012. To meet these regulations, a further reduction of emissions is required. The particulate matter (PM) emission amount, for example, needs to be reduced to 1/20 compared with the required level of the conventional regulations. MHI has developed the D04EG engine in compliance with the EPA Interim Tier 4 emission regulations, which reduce the regulated substances further than engines certified the conventional regulations, while also attaining higher fuel efficiency.
