I'll add a little feedback on running the 245/40 275/35 (vs. old Star Spec 235/40 265/35 combo on stock wheels.
As Kgolf (and The Hack, and others) pointed out, this is may be too wide for the stock wheels, especially on track (and maybe more so with Michelins given the rounded vs. Star Spec square design). Technically it's within the recommended rim size range, but there were issues for me. And this may be more of a track-use related thing vs. a street use thing.
Confounding Factors Lower profile sidewall on Star Specs
~700 miles on the PSS, maybe not fully "broken in".
Results Significantly less grip in braking, in, and out of corners
DSC was very active. ( I usually run with it on for the first lap, maybe the first session, but had to leave it on this day.)
DSC active in corners (no traction rolling on to throttle at apex) where I roll on full throttle and never have issues.
More front end slip--understeer
Understeer in, oversteer out 
No confidence!
Lap time off by 7 seconds (same alignment settings as usual too)
Temp on the middle of the tire tread was 30+ degrees hotter than the inside or outside readings on all 4 tires using an IR gun (my friend had an IR gun, but no pyrometer). Contrast that with my friend's even temps across the tire, and Skelekitty's more even tire temps.
Notes For those thinking it might have been an "off" day, I took out Skelekitty's car, with 2.5 year old Star Specs that have seen 7 track days and 15,000 miles (pretty heat-cycled and hard) and was 1 second off my usual time. Our cars are identical, same suspension, alignment, mods.
I really didn't notice much difference on the street (I don't drive anywhere near how I do on track), but there's a big difference on the track.
Plans I'm going to mount these on wider wheels (9/10) and give that a shot. I had planned to do this before my track day, but life got in the way.