What size battery does the 2003 ford mustang use?

The 2003 Ford Mustang can make use of either a Group Size 58 or a Group Size 59 battery. It's recommended You get at least 550 cold crank amps in whatever You purchase: AutoZone or Walmart will have compatible batteries between $100 and $200, dpending on if You go with an AGM one or not. Some indicators that it might be time to start considering a replacement battery are that Your engine is slow to crank (Feels sluggish and takes longers than normal), the lights are dim and You have other electrical issues, the check engine light comes on, Your battery has exploded under Your engine's hood, warping the metal of it, or if it's older than 3 to 5 years.