What Size Spacers for 18 inch Porsche Wheels?

[ChrisZang]

well simply measure how much space is left between the outside of the tire and the inside of the fender well
That;s the size spacer you need

[Johnny Danger]

To put things in perspective, most enthusiasts who upgrade to 18 or 19 inch wheels who are targeting a "flush" look, typically run fronts that are either 8 or 8.5 inches wide with offsets ranging between +38 to 45 depending on the width and rears that are 9 to 10 inches wide, with offsets ranging from +30 to 45 depending on the width . These are general guidelines, and things such as tire size, suspension set-up, as well as how "aggressive" one wants to his or her vehicle to look, can vary between fitment .