Ok, my 8 is mostly bone stock, no lowering, no suspension upgrade. It's rolling on stock rims and kuhmo all weathers right now, but I want the sick looking charcoal rims on the new r3 model rx8 and I've found some, but I want to be sure I can change my tires from 18 inch to 19 inch and not have anything catastrophic happen. I'll need to buy new tires of course, but other than that, would it all work fine?

 

If you maintain the same width and offset, there will be no problem. To maintain the same tire diameter, the proper size would be a 225/40 or 245-255/35 19.