Anyone know what size tire I would need to... 1. Keep the overall diameter of the wheel\tire the same. 2. Have the sidewall even with the edge of the wheel (no muscle car tire bulge.) Also any recommendations on tires as sticky or sticker than the stock RE070s or places to buy\mount them? The DHL guy called and my GramLights will be here soon!!!!!
I'm guessing either a 40 or a 35 series. Not sure about tires. You looking for an allseason or uhp summer tire?
I think this is right, someone please interrupt me if I'm smoking the wrong kind of crack. If you are looking to maintain a stock sidewall height I think it would be 101.25mm if you take 45% of the stock tread width of 225mm. If you take 1/2 of the difference between your 17 and 18 inch wheel which is .5 inches and convert it to milimeters it comes out to 12.7mm ( rounding up to 13mm) I think this would be the difference between the sidewall height you need on an 18" rim and what the stock 17" rim comes with. Subtracting 12.7mm from 101.25 gives a desired sidewall height of 88.55mm for the 18 inck wheel the way i see it. Here's what I came up with: 255/35 = 89.25mm sidewall < close but probably wont clear 245/40 = 98mm sidewall 245/35 = 85.75mm sidewall < looks good, not sure about rubbage > 235/40 = 99mm sidewall 225/45 = 101.25 sidewall 225/40 = 90mm sidewall < what Tirerack recommends for 18x8.5 rims 225/35 = 78.75 sidewall
If you push anything lower than an offset of 40 or so, you will be sticking out of the fenders some. Here's what ET of 35 looks like on my car. Flush, yet slightly out = stout and awesome.
same tire size and rim on mine http://www.wrxatlanta.com/forums/attachment.php?attachmentid=1302&d=1157819575 Sti's have a bit more room