* 225/75R16: This was a very common size.
* 245/75R16: Also frequently found.
* 30x9.5R15: Less common, but used on some models.
To know the *exact* factory size for your specific 2005 Jeep Wrangler, you should:
1. Check the sticker on your driver's side doorjamb: This sticker lists the recommended tire size and inflation pressure.
2. Check your owner's manual: This will also specify the recommended tire size.
3. Look at the sidewall of your current tires (if they are original): The size is clearly printed on the sidewall.
Without knowing your specific trim level, it's impossible to give you a definitive answer.
