140,000 miles I've put 20,000+ on it this last year. Three tires are good tread still, but one snapped an internal belt and is balding quite quickly. I'll test them in a minute. My dads a mechanic but I never have a time to see him. So I figured id ask here if it's something I can figure out myself. I can change them, my dad has taught me tons. I just can't tell if they're going bad.