i'm not exactly sure how many miles i have on them but I have 52k in my vehicle right now. so anywhere from 15-25k give or take. i could be wrong. Can you elaborate more on the caster? the tires started with a slight noise and it drove them from texas to colorado without issues when they were new. However, now they're too loud like if they were mud terrains. also the the vibrations got worse over time and the vehicle feels more loose on the highway. I automatically put the blame on the tires due to the overall symptoms which progressively worsened as the tires wore. I may be wrong, I do love the aggressive look of the tires so if it maybe something else then i could have that checked.