- Base V6: P225/65R17
- GT: P235/55R17
- Bullitt: P235/55R17
- Mach 1: P245/45ZR17
- Cobra: P275/40ZR18
It is important to use the correct tire size as specified by the vehicle manufacturer. Using tires that are too large or too small can affect the vehicle's performance, handling, and safety. If you are unsure of the correct tire size for your 2003 Ford Mustang, please consult the vehicle's owner's manual or a qualified tire dealer.