EMan 928

I have a set of D90's on my Euro. Rear wheel is 9x16 with 52 offset. Tires are 245/45/16, which is the tire size Porsche put on that wheel. However, doesn't it look like the tire is too small for the wheel? On the front wheels, the tire is closer to the outer rim.

928cs

Which brand\model are your tires?
The width varies between brands.

I like Bridgestone S02 on this kind of rims.

EMan 928

They are sumitomo and are no longer available.

76FJ55

a 9 in rim is capable of handling a wider tire even though Porsche speced a 245. I'm running 265/35-18s on my 9X18 Panamera wheels. when looking at tires most manufacturers specify a range for rim width fitment.