New question, didn't want to open a new thread. What tire size do you think would be beneficial if I wanted to run a 18x10et20 square setup? I was thinking 265/35 all around? Maybe 275 in the rear with 5mm spacers to make it a bit more flush? The car would still have a modest drop to fill out the fender gap. Would I need spacers to avoid hitting any control arms up front? I know rolling the rears will probably be necessary.

 

If you're running square, most people running your setup mention 275/35-18 even though the diameters are off (~1" short out back) which, to me, isn't optimal. If you do this, watch out for VDC errors if so equipped.

Personally (here we go again...see all my remarks this week alone on tire sizing, haha), not a big fan of square setups other than for track where steering response, while still key, is less of a concern than ultimate grip. In this case, use mechanical adjustments, sway bars/springs & shocks to tune the chassis/steering attitude versus relying on tire setup alone.

Elsewise, I'd still run a stagger tire setup.... 255/40 & 285/40 for a good tread width OR the old standby, 255/275.

It really all depends on the intended usage, which wasn't mentioned.

General:

Track - square works (but again, watch for VDC errors)

Street or Street/Track - stagger

Emphasis: this is MY preferred way. YMMV

EDIT: You shouldn't need spacers at +20mm offsets unless yer going for a more stance look. +20s are functional though, possibly at the expense of some parking lot points. Only time you might need spacers with those sizes is for brake clearance. If you're not running Brems or Nissan Z34/G37 sport brakes, you should be fine sans spacers.

 

Okay, so you a staggered tire setup on a 18x10 all around would probably suit me best since for the most part this will just be a pretty daily. Maybe some spacers will happen for the parking lot points Maybe a 10mm spacer in the rear just to get it a bit more flush.

Do you think the 255/40 on the front would rub with about a 1.2-1.5 inch drop? Would 255/35 be a better option? I know the back will clear no problem with 275/40 with a roll.

 

No. And no.

Go back to post #10 in this thread and read the part about VDC. 6% differential in wheel speeds F-R will not even allow you to drive down to the gas station to air up your tires.

Stick with 255/40 or, better, if you're concerned, go with the #1 standby setup, 245/40 and 275/40 combination, so close to stock diameters, they might as well have programmed the car around this combo. If you have any clearance issues in front, it will be with the fender liner bolt which is easy to fix: cut it. If you have any clearance issues in the rear, it will be with the upper fender lip - most likely on the right hand side of the car, if not both.