Been using that calculator all day, that is really a handy visualizer. I've leaning towards 15x8, would like a 9 but they don't make them in 15, Wheelsmith does a custom backspace. Or can save some money and do 16x8, backspace is a 1/4 inch less than I wanted and tire sizes are limited to a 235 vs 255 in a 15. Decisions... the ever present battle with my cheap side.