A fairly recent design of a diesel-engine.
This type of engine is more efficient and more quiet than a regular diesel engine, and because it is an injection engine, it provides a much bigger punch.
Fuel in the common tube, or rail, is under a set amount of pressure which causes the fuel to be atomized. This allows the fuel to combine with the air much more efficiently. With proper direct injection, fuel use is highly efficient, with much less waste fuel escaping the system unused..
The main difference with other injection engines, is that a CRDi only uses 1 tube to inject the fuel, and normal injection engines use a seperate tube for each cylinder. This way the pressure level will be the same in each cylinder, causing less vibration and noise.