It's an irritatingly long
It's an irritatingly long-standing myth that the octane rating has anything to do with horsepower. Simply put it effects the stability of fuel at various compression ratios until combustion occurs. The fuel itself has EXACTLY the same energy in it. If Ford is indicating use of premium fuel its simply because the compression ratio is high enough to warrant it to prevent engine knocking. If the compression ratios are increased that's one way that additional power can be generated but its not the fuel.