Advantages of Piezo Injectors
Rapid injector switching
Up to 7 injection pulses per cycle
Expensive to construct
Cheap to construct
Much tougher internals
Only max 5 injection pulses per cycle
Harder to control fuel delievery
Many car manufactors used piezo bosch injectors for 2006 to 2010 to meet the necesscary emmisions targets.However advanses in dpf construction and engine mapping has allow a rebirth of solenoid injectors.
This however will be sort lived as the ever more stringant euro targets means the more metered fuel delievery of piezo injectors will once again come into play.
Expect piezo injectors to appear in large numbers within the next 3 years