2009 MS3 Rims/Tires/Drop Questions

[dexter]

After some searching I've found that I've still got some questions about wheel fitment for my 2009 MS3. I'm currently running a stock wheel and suspension setup. Research has lead me to believe that my specs are as follows:
Width - 7 inches
Offset - 52.5mm
Tire - Bridgestone Potenza 215/45-18

I'm getting to the point where I'm going to need to be replacing my tires and am considering getting rims while I'm at it. The rims I'm looking at online are 18's but are 8" wide with a +45 offset. Tire Rack is still recommending a 215/45-18 tire. I don't really know much about this kind of stuff but it seems strange to me that the tire will remain the exact same size even though I'm moving to a rim that is an inch wider. My main concern that at stock ride height, will I rub moving to an 8" wide rim with the OEM tire size? Should I be switching to a wider tire like a 225 maybe?

Following that, I'm also considering lowering on Pro Kits (don't want to go super lower, just hoping to eliminate a bit of wheel gap). If I go with the Pro Kits and go with the 18x8 +45 offset will I rub without rolling my fenders?

Thanks for the help!

(Sorry for the noobness. I searched around a bit and had a hard time finding answers for what I was looking for. Any answers or links to helpful threads would be great.)

[sammifan]

I'm running 18x8" +45 rims exactly like the ones you want to get. I'm also lowered on Pro kits like you plan to do. I had 235/40/18 tires and they rubbed slightly (only on the big dips). Rolled my fenders and no more rubbing. I'm on my second set of tires and I went with 245/0/18 and once again I rub slightly on the big dips. If you insist on not rolling your fenders, then stock tire size will fit fine on 18x8" with a slight stretch but not a big deal. To me however, that defeats the purpose of having wider rims.

[dexter]

I'm running 18x8" +45 rims exactly like the ones you want to get. I'm also lowered on Pro kits like you plan to do. I had 235/40/18 tires and they rubbed slightly (only on the big dips). Rolled my fenders and no more rubbing. I'm on my second set of tires and I went with 245/0/18 and once again I rub slightly on the big dips. If you insist on not rolling your fenders, then stock tire size will fit fine on 18x8" with a slight stretch but not a big deal. To me however, that defeats the purpose of having wider rims.

Awesome, thanks for the reply. The main reason I'm thinking about going with an 8" rim instead of the 7 was because it seems like most aftermarket 18's I like are an 8" width. I'm mainly thinking about it from an aesthetic point of view.

Am I going to notice a big performance benefit from switching to a 225, 235 or 245? I was hoping not to have to roll my fenders at all but if sizing up tire wise will offer a reasonable performance benefit I'd consider it.

Glad to know that I can still lower a bit and not worry about rubbing a ton if I stick with the 215's on an 8" rim. Thanks again for the advice!