What Does Shoulder of Tire Wear Mean on a Ford Edge?

[Nicko]

Hey folks, just noticed the outer shoulder of my tire is worn way more than the rest. I drive a Ford Edge, and I haven’t been off-roading or anything crazy. What could be causing this? Is it alignment, tire pressure, or something else? Should I be concerned about safety, or can I wait a bit to fix it? Help me out before my tires get even more bald, lol.