I have an 08 GT and I was talking to the sales guy and he said that these cars are tuned for regular gas and that you wouldn't notice a difference between regular and super. I find that somewhat hard to believe, can anyone confirm this?

You lost me?![]()
I drive it so often I fill up on avg 3 times per week! I avg just over 21 MPG with mixed driving.I run regular 87 octane. I have the 89 and 91 bamachips tunes but i have yet to use them. Cann i fill up with 91 octane on the 89 setting?