Thanks for the help guys. I can understand the 8 inch width arguement. I was going to run 235's on my car. The grids come in 17x7.5, 17x9, 17x9.5, 18x8.5, 18x10 and 18x9.5. What do you guys think I should get with those options? Dave, how much heavier are these wheels? The last thing I want to do is decrease performance in my car. I understand that I will be greatly increasing my handling performance with the new tires, I just don't want to lose to much in acceleration. Thanks again everyone. Corey
Jeez, forgot they jumped up like that in width. Well look at it like this.
Every inch wider you get, you get an extra inch wide strip of metal added to the outside of the wheel equal to the circumference of the wheel, making wight gain all too easy.
If you're set on these wheels, a 235 will fit with some 'meat' on the 7.5's, but the sidewall may feel a bit squishy for you, even if the absolute grip increases on a wider tire. If you get the wider ones, you can fit your 235's and if you want to start racing seriously at some future date you can definitely just stick some fatties on there instead of buying new rims.
You have an EJ255 which was underrated from factory anyway in your car. I say the width is worth it, in my opinion, as I like wide wheel/tire combos. ALSO, your car may be 'technically' slower by some stupidly small amount(like a .1 second reduction to 60mph), but it might not feel slower, and you can grip and rip in the corners anyway.
Here are 3 wheels/tires I've run and their weights, which i found kinda remarkable.
-JDM Subaru V7 STi 17x7.5's with 235-45-17 Kumho ASXs-44 pounds
-JDM Subaru V5 STi 16x7's with 225-60-16 RE-92 Potenzas-44 pounds
-Generic brand 5-spoke Tire Rack Specials 18x8's with 245-45-18's Kumho ASXs-44.5 pounds
Though there was almost no weight difference, the distrobution of weight in the wheel/tire combos was very different but did not noticeably effect performance. This was on my Baja Turbo with the same engine as you and a full 3" turboback and tune. The only difference I felt was a lack of wheelspin with good tires.