165/50 is a harder tire to find....last time I ordered a set I had to get coopers and they got shipped from germany... 165/45 federals give a nicer stretch but only problem with those(if theyre going to be on a dd) is that if youre running a 195/50 and put those on itll automatically drop ur car 2.5" and youll have a wheel gap so youll have to go even lower to make the set up look decent (busted oil pan/hard parked).....my advise is keep the 175s or pay the 600 I paid for 165/50