I am looking to buy some 18x8 or 18x7.5 rims for my 2003 G35 Coupe. I know that it has 225/45/18 tires in the front and 245/45/18 tires in the rear. My question is do I have to get a certain sized rim for the front and another size for the rear if I want to reuse my existing tires, or will the different sized tires fit on the same sized rims (i.e. could I get both the 225's and the 245's on 18x8's)? Thanks for the help.

they will work, going down in size is kind of pointless but saves money.

My 245's fit on 18x8's . Check www.tirerack. com in the specs for tires you like.