Are you rubbing over bumps or at full lock?
I am running 265/40/R18 Michelin Pilot Super Sport tires on all 4 corners with no issues at stock ride height. Hope to get some pictures soon.
It looks like from this thread 275/35/18 should be fine with H&R/FG2 combo. If anyone thinks any different please chime in I am ordering wheels tonight, tires tomorrow.
I run 265/40/R18 Michelin Super Sport with only very occasional rubbing on the unrolled fenders. You might need to roll the fenders a little.
Snow is finally gone and installed 275/40's all 4 corners as promised. They are very tight no more than an index card clearance against the upper control arm joint. I had to raise the ride height some to prevent rubbing against the bumper extension liner.
No rolling here, but it wouldn't hurt, On large bumps I sometimes rub.