In 2004, a new range of Pumpe-Düse (PD) Unit Injector diesel engines was offered. The design employed unit injectors along with additional electronics and emissions equipment to meet emissions standards in Europe and North America, and is more complex than diesel engines previously offered. To accomplish the task of producing sufficient power while meeting emissions standards, the "PD" technology injects fuel directly into the combustion chamber at pressures up to 2,050 bar (30,000 psi). The purpose of the high pressure...