stoon aucoin

i have an 06, std trans. mustang gt. i recently installed cold air induction and a scal tuner. i had a guy w/ a mustang dyno custom tune the car w/ a regular octane tune and a premium octane tune.
i showed up with the car filled w/ premium octane. here's what puzzles me, both tunes put out almost identical performance stats. one would think that the high oct. tune would put out significantly better numbers than the reg. octane. Are the stats almost identical because the reg octane tune was set while running premium octane? thanks! oh yeah, i'm getting 285hp and 305torque at tire.