It is tire time for me! I mainly just run HPDE4 and autocross with friends when I can. I’ve deduced I want some RS-4, but now the question is which tire size? My gearing means my car is out of ideas at 123 mph on 285/30/18 but data at roebling shows power band was tapped out earlier and i was at 129 on a taller tire (275/40/19). The correct answer obviously is switch back to 3:27 gear, but I digress. So I’m also concerned about width and sidewall height. Shorter sidewalls generally mean stiffer, correct? So should I go 285/35/18 or go 295/40/18 for better sidewall height that should save 4th gear to 130 mph? In my v6 auto, it’s out if ideas at 5th gear when it goes to 4200 rpm. So my pros of each right now are... 285/35 -$50 a corner cheaper -maybe a stiffer sidewall? -less risk of fender rub (my v6 leans a lot) 295/40/18 -better top speed on straights at Road Atlanta, VIR, etc -and thats it... I’d appreciate feedback!