Aug 29, 2014 at 11:32 AM
Ford can't help you with this since they only deal with stock parts/tunes.
If you are looking to save money, don't use a tune that costs money and requires more expensive fuel.
If nothing else is done to the motor then the higher octane tune will not do much anyway.
Your car needs 87 octane fuel, no more unless there is a problem that you aren't fixing.
To get a tune you only need a handheld tuner and a person to tune the car(there are a few options online).
There are things that you can do that don't require a tune like underdrive pulleys, a larger throttle body, aftermarket Mustang plenum, headers, etc.