In my short knowledge and a bit of reading at PDF, my words as follows.
No doubt, PAF is satisfied with RD-93 performance which provides more power than RD-33 but having a less life. Not to forget that officials stated to be satisfied for the time being so it could be like waiting for better alternative that can surpass the necessity/need of RD-93 with more power, life and support.
Also to remember, WS-13 is almost closing to finalization phase and soon (I hope) would be announced for production. Furthermore, we are looking for advance/better avionics like AESA, IRST etc for upcoming JFT block-III which warrants the necessity of more power and RD-33 lacks the same in front of current JFT engine, RD-93. It was also discussed by many senior members that even RD-93 may not be able to handle all that power and doubts were told but the few shared that RD-93 may accommodate the required power of AESA tailored for JFT having a smaller size while keeping in view the nose-cone of JFT but in conclusion we may feel the requirement of more powerful, long life and reliable service after sale engine.
IMO, it was like to stick with RD-93 for JFT Block-I & II until & unless Chinese engine or to the some extent we have hands upon engine like EJ-200 but seems like it is going to be WS-13 for future blocks of JFT including JF-17B. Also to remember that on many occasion, we have been expressing our reservations with respect to relying on West or US so also we have some kind of "not to be trusted" thing that the sale or spares could be blocked any time in case of controversy or things gone wrong so in this case, China is to be trusted more than them that stands with us as proven on many occasions in past. Rather to rely upon moody friends, better to be in the company of trustworthy. EJ-200 is not alone product of England but consortium includes 3 countries so going for the same engine is like to deal with all these partners especially Germany and never to make angry anyone of them that can effect our security, money, time and above all delayed induction of an engine (WS-13) from reliable friend, China. However, if we succeed to secure the any arm deal for any of our forces from any of these nations, might pave the way towards something like EJ-200 but chances are less.
Indeed, RD-33 holds more life than RD-93 but lacks power that would be required in future blocks due to integration of AESA, IRST etc. so in my humble opinion, any engine powerful than RD-93 with more life would make it to PAF for JFT and while looking at current situation and our relations with West, US and all, seems like it is going to be Chinese that we can trust more than others. We have to keep in view the expected future induction of FC-31 as well which may fly with WS-13 so to avoid maintenance hurdles and dealing with different parties, we might go for WS-13 in JFT along with FC-31 so that will be easy to maintain and help manufacturer to increase its reliability more than before.
However, I can be wrong in my observations or findings though the words or correction by any senior member would be appreciated.
