Common Rail Injection System

Hello Automotive Lovers,

I wonder the missery behind the common rail injection system. You all know that the indirect injection system was built in order to provide lower noise and lower exhaust emission for the passengers cars. But recent technology turns the disadvantages of the direct injection system into advantages by using common rail injection system. Could you explain me how does the common rail injection system works? What is the main differences between old technology of DI systems and recent one?

Common Rail:
-More efficient
-Can provide high injection pressure (1800 bar)
-Less noise
-Less exhaust emission

But I wonder the physics behind the improvement of the DI systems.

Thanks All.

To get a concise explanation of the practical and theoretical operation I would suggest Googling "common rail injection" which is common in modern diesels.