From what details are given in Pixar's YouTube video description..
Blindsided by a new generation of blazing-fast racers, the legendary Lightning McQueen (voice of Owen Wilson) is suddenly pushed out of the sport he loves. To get back in the game, he will need the help of an eager young race technician, Cruz Ramirez, with her own plan to win, plus inspiration from the late Fabulous Hudson Hornet and a few unexpected turns. Proving that #95 isn’t through yet will test the heart of a champion on Piston Cup Racing’s biggest stage!
..this looks like it will be a comeback story underneath it all. It certainly works as the third film in the franchise. The direction Cars 2 took wasn't exactly high-praised to begin with, and it wasn't really a film made for adults, even though there were plenty of nods to popular culture for previous generations to understand. Not exactly sure how this film will cater to an older crowd, including the young crowd that grew up with the first Cars. Following trailers leading up to the June 16, 2017 release will give us a better idea on what Cars 3 will really be like. So far we like it!