Okay then - this means (using your examples) that a 225/55-16 would be almost an inch (22mm = .87") taller overall? Is that correct?
225 x 55 x 2 = 247.5mm
205 x 55 x 2 = 225.5mm
= 22mm or .87"
That's a significant height change!
My real question then is, why don't people seem to use this factor when attempting to raise/lower their cars (I mean just change height -- not performance issues -- pure cosmetics)? It just seems like one could get even a small adjustment to height by using a small tire size change. For example, if I wanted to raise my car 10mm (I just put on H&R springs and Bilsteins), why couldn't I just replace my stock 205/55-16 tires with 215/55-16s? That would give a height difference of 11mm, if I'm calculating and understanding this concept correctly.