That is a blunt lie. It is the western that often exaggerated while the Chinese used the most reasonable spec to promote their products.
Check out PL-12 BVRAAM and KLJ-7A AESA Brochures indicates at airshow.
The biggest bragging king is the west who overstate and overestimate their products capabilities.
Ya offcourse, Chinese are the most scrupulous businessmen in the world.