Originally Posted by sc00by4life
You're numbers are off. The 18x9 +45 has 3mm less clearance than the OEM sti setup, 5mm less than OEM wrx. 18x9 +45 has about 1mm less clearance on the inside than an 18x9.5 +38.
You will run into inner clearance issues when running larger tires with stock struts.
I had the understanding that the OEM STI setup was 18X8.5 +55. If that's the case then 18X9 +45 would have 4mm more inner clearance. Let me know what the actual OEM STI setup is if I got that wrong.
You are right that 18X9 +45 has 1mm less inner clearance than 18X9.5 +38 (18X9 +45 = 5mm less clearance than WRX, 18X9.5 +38 = 4mm less clearance than WRX, 5mm-4mm=1mm). I didn't mention that specifically, only that 18X9.5 +38 was 4mm tighter on the inside than OEM WRX. Both have more clearance than the OEM sti (if my above assumption is correct) so unless the WRX struts are significantly different than the STI in that area then I would think there should be no issue?