Re: will this work?
Hey no need to apologize. I didn't mean to be harsh but this sounded like something we just went over. If this helps at all the backspace should stay about the same whether you are talking about 17s, 18s, 19s or even 20s. What changes is side wall profile - example 235/45-17, 235/40-18, 235/35-19 are all about the same overall diameter (25.32 - 25.4 - 25.47) but the sidewall gets shorter as the wheel diameter increases. So a 235/45-17 and a 235/40-18 almost interchange. The sidewall is a little squarer but they all need about the same amount of room.