I got this answer from the guy from the dealer who sold me the car and is a car guy.
"I can't give, nor can I get a concrete answer. Fuel economy figures are calculated with "min 87 octane". However, that said, a friend of mine was an engineer at Ford, now runs his own business, believes the car will make more power on premium fuel simply because the anti-knock sensors will not retard the ignition timing as early in the rpm range.
He did say, the difference would likely not be enough to be noticeable, nor would it have enough of an effect on fuel economy to make it viable.
Thats as good as I can get."