i dun get it either but i switched from stock 18x8 +30 REAR wheels to 18x9.5 +20 wheels.
the chamber DID get more negative. alignment not done yet but the chamber is more obvious.
looking for SPC rear chamber& toe kit now

 

just get the car aligned and get camber and toe right in the middle then once suspension goes on check alignment again i really doubt you will see a hole lot of tire vear maybe only in the front because i beleive the rear has no adjustments so you really cant nothing about that

 

redlude97, now I see what you are talking about and that makes sense. Good job on explaining it.

 

Yes, while the way I explained it is true, it may not be the case in the real world. I all depends on the thickness of the spacer used, the spring stiffness/linearity, and the amount of negative camber initially present. At low values of negative camber, the rotational component plays a smaller role than at a higher level of negative camber, so negative camber + spacers = more negative camber unfortanetly, so if you are running a large drop with soft springs, the affects will be more noticeable than for someone at stock height with the same spacers