Higher efficiency - 2 stroke or 4 stroke diesel engine?

[ank160]

Hi evry1!

Just wanted to know that which has got higher efficiency - 2 stroke diesel engine or 4 stroke diesel engine. I believe that direct injection of fuel in diesel engines prevents the loss of unburnt fuel in exhust of 2S engine. And simpler mechanism and lesser no. of moving parts in 2S dsl engines makes it more efficient than 4S. Am i thinking in right direction? Plz help.

 

[Spinnor]

This is an interesting read,

http://en.wikipedia.org/wiki/Wärtsilä-Sulzer_RTA96-C#Efficiency