Wheel spacer question (not just a what fits)

Jhill

So trying to figure out wheel spacers for sport rays and if I even want them. It would be nice to go a little flusher but not wanting to have any ill effect on handling so doing the math vs the Nismo rays (a known good) a 13mm spacer front and rear would equal the same outer distance since both rims are .5 wider and 7mm less offset so 12.7/2 = 6.35, 6.35+7= 13.35. So I guess a 15 would be the closest option for outer limit. Question is though by doing that I am moving my whole wheel centeriline out 15mm where the Nismo centerline is only getting moved out by 7? What effect is that going to have on my scrub radius for handling?

It's odd the two models have different scrub radius I would think they would have tried to keep them closer?

Just trying to figure out the best track width/spacing for handling and not picking up any bad characteristics.