good info .. all on 1 page!
(the PDF is better quality)
http://74.125.155.132/search?q=cache:HXrbpGRZZ_QJ:www.caranddriver.com/content/download/107583/1458928/version/2/file/2009%2BInfiniti%2BFX50S%2B-%2BSpec%2BSheet.pdf+fx50s+wheel+size&cd=1&hl=en&ct=clnk&gl=us
(the PDF is better quality)
http://74.125.155.132/search?q=cache:HXrbpGRZZ_QJ:www.caranddriver.com/content/download/107583/1458928/version/2/file/2009%2BInfiniti%2BFX50S%2B-%2BSpec%2BSheet.pdf+fx50s+wheel+size&cd=1&hl=en&ct=clnk&gl=us