rubber Q.

so my wheels i wanna run are 8" wide, wich is 203.2mm, so my ideal tire would be say a 205 40r 18? i know imma need rubber to be a bit narrower than rim, as shits gonna be close w/ tuckin, but do i needa go all the way down to 205? or may i be ok with some like 225 40r 18s?

I would do 225 cuz I'm gonna be runnin 235's on my 18" 8's when I get 'em but I like as much rubber as possible for performance but I wouldn't go 205. It would be easier to POP the bead off with 205s :-/