Wheel fitments... 15X wide

[NoHachi]

Interested in this as well.
I have friends with miata's that have experimented endlessly with tire size vs rim size vs speed. They all run 225-45-15 on 15x9. or 205-50-15 on 15x8. The 225 tire on the 8 inch rim just wasnt as fast as the 205 and communicated a lot worse. Maybe something to keep an eye at. Lately they are upsizing again to 15x10 and 235 tires some even 275.

Clearance between front tire and strut (60mm coilover springs) was 2mm on mine. 15x7 ET10 195-50 tire. So any extra width needs to be added towards the outside. I think you would be looking at a:

15x10(slight stretch to keep tire in its happy place)
ET-70

No way that will ever fit under standard guards. Thats the reason most N2 cars run widebodies and they are mostly using narrower tires then you plan on running. It's also a move in the wrong direction for front vs rear trackwidths.