* The sticker on the driver's side doorjamb: This is the most reliable source. It will specify the original equipment tire size.
* Your owner's manual: If you have it, the manual will list the recommended tire size(s).
* The tire size stamped on the sidewall of your existing tires (if you still have them): This will tell you what size was previously on the truck. However, this might not be the original size if they've been replaced.
Without this information, it's impossible to say for certain what size tires will fit your specific Ford Ranger. Common sizes *might* include things like P205/75R14 or P215/75R15, but these are not guaranteed to fit your truck. Incorrect tire size can affect speedometer accuracy, handling, and even cause damage.
