The OP later says on different threads that he has rubbing and that he’ll definitely go 245 next time:Do you know where his comment was about 255 not being a good size? Personally I think it might be perfect. See this link: UPDATE: 255/35/20 Michelin Pilot A/S 3+ fitment on Performance Model 3 - And first use of the parts catalogue! : teslamotors
Here's one of the OP's comments/reply: "It’s the upper limit of acceptable. People do put 265s on 8.5 inch wheels, but its not ideal and starts to get pretty risky imo. Honestly I think 255s are great on these particular wheels - theres a lot less sidewall sticking out past the lip than I would have expected based on the 255s (also AS 3+) I ran on my STi with the 18x8.5 inch oem BBS"
Tesla model 3 rims : TeslaModel3
I found the answer to my own question. The motor trend article about track mode says “10mm wider” than stock rather than saying 245 when talking about Tesla Engineering sportcup 2 setup. Made all my google searches not hit. I definitely don’t want the cup 2s for street use. Now I can happily sleep at night and buy the 245s.