can't attach anything right now, was gonna do a screen grab, but go here:
Sizes To Fit Your Vehicle
ProjectM96, your tire dimensions front and rear match that of a '99 996 with 17s. Again, I don't know if that means they just threw on different size tires or the wheels were a bit wider for a 911, but I imagine it's the latter.
These are the dims for a '97 986:
Sizes To Fit Your Vehicle