Chinese military expert Du Wenlong said in a recent interview that J-20 stealth fighter might have used new-type power system, which is made by China, and therefore achieved overall homemade.
Du speculated that after test of Number 2011 fighter, J-20 might have entered the status of prototype, and is now performing ground high-speed sliding test. He said since Number 2001 and 2002 J-20 aircrafts had made similar test, there would be no necessity to make such test again if the power system were not replaced.
Besides, Du said he noticed that recent pictures of J-20 fighter is using an engine shorter than the old types, that might mean that it’s a totally different engine, and should be an important signal that J-20 stealth fighter will use new engines.