Its not about the wheel diameter.
All porsches have staggered setup since.. like forever.
After 65 i believe.
For example if u see 19 x 9.5 fronts and 19 x 10.5 rear, then its a nogo.
Most importantly, any newer porsches with rear steering does not recommend tire rotation, (not even side ways) which the person above proclaims he own.