By putting the tires on the other rim across from it from the side, (just moving it keeping the tread in the same direction, no flipping the tires over) your putting the inner track to the outer track for a even wear. You cant just swap the tires on the rims their on to the other side, because the tires are unidirectional and it would put the tread backwards. Or just do what I do and get a lifetime alignment and have it aligned all the time. I think I paid my Firestone dealer 50 bucks for one. The other is just an option..:-)