I think it says min 91 octane, some states only have 91 and most cars that need the higher octane says premium fuel only,, i'll bet that if you add oct booster or can get 93 octane or a little better, your car will get better mileage.

I have race fuel, and even on the street i try to add 3 gal to a tank of gas. with my v8 running 95 octane i get 22 mpg , yet with only the 93 i only get 18.5 does it offset the cost maybe not but she runs so much better, jim