The specific octane rating recommended by Ford is 87 octane. However, you can use higher octane fuels like 89 or 91 if you prefer, although it won't provide any noticeable performance increase with this engine.
Important Note:
* Do not use E85 (ethanol blend) in a 2011 Mustang GT as it is not compatible.
* Always consult your owner's manual for the most accurate and up-to-date information.
