PD, which stands for Pumpe Dse, is a fuel injection system used in Volkswagen engines. It is a direct injection system, meaning that fuel is injected directly into the combustion chamber, rather than into the intake manifold. This results in better fuel efficiency and power output, as well as reduced emissions. PD engines were first introduced in 1997, and they are still used in some VW models today.
PD engines offer several advantages over traditional indirect injection systems. First, they are more fuel efficient. This is because the fuel is injected directly into the combustion chamber, which means that there is less chance for it to evaporate or condense before it is burned. Second, PD engines produce more power. This is because the fuel is injected at a higher pressure, which results in a more complete burn. Third, PD engines produce fewer emissions. This is because the fuel is injected directly into the combustion chamber, which means that there is less chance for it to create pollutants.