I tell you this. it is way to hard to tell.one thing it is feel thing about how much pressure you use to get that ..pattern. I use a 3ft bar to loan /put pressure to get the pattern.. you can not loan it like it would be in the car. so how do you ask someone how much pressure did you use to get that pattern?..I going to asume he doing this by hand with light pressure. he is not far off. I see them be dead on and the rear end make noise. I see where you think they would make noise and don't..I do this for a living I build at lease one a week..