Article has loop holes but here is my take on Sino Diesel Electric Subs. Modern Chinese AIP equipped subs are as deadly as any contemporary sub in the world. Yuan is already AIP quipped and has been updated thrice already. Qing is another story. As far as i know, Chinese have been working on AIP tech since early 90s and have invested heavily in this technology alone. The Sino Sterling counterpart has three flavors i.e. 80KW, 120-40 KW and goes upto 200 KW. Song, Yuan and Qing all are equipped with AIP propulsion which makes them extremely difficult to detect due to virtually no noise generated. Pakistan Navy has been in love with Agosta 90Bs for this very reason, AIP subs are silent hunters.