The core breakthrough of the J-20's supersonic cruise capability stems from the successful deployment of the domestically produced WS-15 turbofan engine, which has a maximum thrust of 18.5 tons and a thrust-to-weight ratio of over 10, surpassing the F119 engine (15.6 tons) of the American F-22.
The core breakthrough of the WS-15 engine lies in achieving "non-afterburning supersonic cruise" (maintaining high-speed flight without afterburner), with a cruise speed of Mach 1.5-1.8 and a measured speed approaching Mach 2.0 at high altitude.
What does this speed mean? In supersonic cruise mode, the J-20 can fly from Beijing to Shanghai in just 25 minutes, reducing the response time for interception missions in the East China Sea Air Defense Identification Zone by 40%, and reaching airspace 800 kilometers away within 20 minutes.