User blog comment:Damac1214/Call of Duty: Advanced Warfare is Built on a New Engine, Says Sledgehammer/@comment-64.131.129.153-20140505042550/@comment-1055346-20140505045115

Too be fair, they weren't wrong in saying the Ghosts engine was a new engine. It wasn't brand new, but those new features made it new enough. And most engines these days aren't built from the ground up anyways. Even the big names like Frostbite, Unreal, and id tech are built off the older generation.