18x8 ET 57 with 245/40/18 and 18x9 ET 43 with 285/35/18 - will I need spacers? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

JayG · 01-29-2015, 11:51 AM

Factory 18's are 7.5J x 18 ET50 and 9J x 18 ET 52 with 225/40 front and 265/35 rear tires

KRAM36 · 01-29-2015, 12:07 PM

Quote:

Originally Posted by JayG

Factory 18's are 7.5J x 18 ET50 and 9J x 18 ET 52 with 225/40 front and 265/35 rear tires

This is what I based your clearance on. Using the same tool BRAN posted.

1010TIRES.COM - Wheel Offset Calculator

If the tires are already on the wheels then I guess 285 will fit the 9" wheel.

This site here gives you a list recommended tire sizes for wheel widths.

Tyre Size for Rim Size/Width Calculator - What's the best tyre size for my rim?