I just got an '09 GTS and I want to get wheels and tires. I want to stay as close to stock size just because, but I keep finding wheels I like that are 18x8 or something other than the standard 18x7. What impact, if any, would a one inch jump in width have on the car (ride, system info, etc.) as well as tire size? That is, if I go 18x8, can I stick with the stock tire size? I'm thinking that a change of that amount shouldn't really effect much, but I wanted to check here first. Thanks.

 

I'm in the same boat. I found a sweet set of rims that are 18x9.5 that look like they will forever be out of my reach.
Those two and a half inches really mess with the inner and outer clearance. It looks like i'd need to get spacers and I don't know if I want to go down that path.

EngRWW33 posted a really good link on a different thread, want to give full credit:
http://www.1010tires.com/WheelOffsetCalculator.asp

I tried playing around with this and it seems like 18x8 would work... But don't run out and buy rims on my say so, because I am a complete noob in the world of wheels.

Post pics of the wheels you settle on, I'm looking for ideas myself.

 

18x8 would work fine...you could also use them with stock tires..may be a small stretch but nothing extreme..now 9.5 i dont know about that..unless you got some kinda body kit to make those wide wheels flow with...or the offset is extremely high i probably wouldnt go with it. theres a thread with a guy who put stock evo x wheels on a lancer and those are 8.5 and it looks extremely agressive..so i dunno.

 

http://www.bigcustomwheels.com/rt_specs.jsp

Here's one more link for today.
Very cool calculator, lets you input your current wheel and tire combo, future wheel and tire combo, and see how it effects your odometer speed and the clearance inside the wheelwell.

Yeah, you're right 9.5 is way outta my league.

 

you gotta worry about the offset also

 

im running 18x8+35 235/40-18 and my car rides fine.. id recomend 18x8 over 18x7 it looks way better and the wider the wheel the more traction ull get on dry roads. for offset make sure its between +35 and +48