Hi
Had my 51 plate tracked yesterday, had been taking off the inside edge
I managed to clip a kerb during the snow we had and the inside edge of the tyre was in a very bad condition so after MOT and a new track rod end I got it organised
Had 4 wheel tracking and they were parallel, should have been -2 according to the book, new tye was on 3-4 months and showed signs of wear on the inner edge
It doesn't need to be out much to make a difference but the guy doing the tracking should set it correctly
Hope this helps
Regards