What is recommended is irrelevant to what is required.
Ford, Chevy et al play this game. They want to list regular on their monroney label to keep estimated fuel price as low as possible, but they want to advertise horsepower as high as possible. Even the Corvette had a "regular" fuel requirement a few years ago, but recommended higher octane fuel in the manual.
Believe it or not, there are enough dumbos buying these performance vehicles that go by what the monroney label tells them. "Aww shucks the label says that gas cost a lot."