I'd say it's impossible to get a full even tread the way they put that is I should have a full F1 mechanic's pit crew ;) for the amount of tread they are talking a curb scuff could make it lighter then the rest making it bend more and use more tyre then should be needed . I'd say it was to cover there own back from the tyre issue and it's been exaggerated to become this maddness of she said he said. I'm not trying to be funny with anyone. And maybe I'm wrong but the tread on tyres and new car's that use the road shouldn't be needing to worry about the tread, other then being to low past the legal limit :D