This'll be off topic, but since you brought up Ford. Have you read about the 2013 GT500 yet?

 

Finally switched to 93 after going 200+ miles to finish off the 87. Only $10 more to fill up over 87 and the engine seems to be running a bit smoother. Didn't feel much of a performance difference...but didn't expect it either. Hopefully mpg's stay the same or improve.