PD = Pumpe Duse
From the Volkswagen website :
Pumpe Düse - which means 'pump injector' - overcomes the problem of pressure lost through fuel pipes. The injector and pump are integrated into a single Pumpe Düse unit. Each cylinder has its own Pumpe Düse unit mounted in the cylinder head and operated by the camshaft, injecting fuel directly into the combustion chamber at pressures up to 30,000psi. These high pressures produce a far more efficient blending of the fuel/air mix, precise control of fuel quantities and injection timings.
Benefits of Pumpe Düse include good fuel economy, reduced exhaust emissions, and substantially increased performance with more torque than traditional injection systems. And the Pumpe Düse engine is relatively quiet in operation, with noise levels similar to those of a petrol engine.
Pumpe Düse technology is exclusive to the Volkswagen group.
560 miles to a tank is very good going indeed I reckon