Just go off the phone with Tire Rack. Wanted to order new rear tires for the 18" G35 rims I just got. Salesperson said that the offsets are going to put a strain on the wheel bearings and if I go with the 245/45 18's I would have problems with ABS. Suggested I run with the 245 40 18's closer to my stock wheel size (225 50 17's) however, still a problem with the offset, with caster etc. Can anyone shed some light on the situation? If I'm going to run into problems, I'd just keep the 17's (it's my wifes car). Who knows, might have a set of 18" G35's for sale.

 

I dunno about all that, but go with the 40 profile. 45 will look ridiculous.