[mfm22]

2003 boxster S. Wheel - 18"
OEM Tires 225/40/r18. Front
265/35/r18 Rear

I'm thinking of getting 2nd set wheels for winter / summer tires.
Do I need to stick with 18" to keep speedo accurate.?

What about the other dimensions ,how much variance is safe ?

Saw a set of wheels. Sized listed 18/8 front 18/10 rear. How can I know if these will work ?

Thanks