I just bought a set of used 18" G35 Wheels for my 2005 Sedan (auto trans) on ebay. They are 225/45/18 front and 245/45/18 rear with Yokohama AVS ES100 tires. I replaced the stock 17's. The fronts struggled to fill the wheel well, while the rears filled it up too much and would rub when turning or going over bumps. The rears also stuck out every so slightly which gave the car a pimped out look (my opinion). The tire package is now listed back on ebay (Item #8024928863) and I'm back to the drawing board. I want a tire that will fill the wheel wells without rubbing and something that will make the car handle better. Should I go to 19's? Any suggestions would be appreciated. I'd like to stiffen up the suspension too. Should I change my springs or shocks, or both?

 

Sounds like you brought the 03-04 G35coupe wheels the offset is just right for the coupe but not our sedans. Changing tires will not correct the fact that the rear wheels stick out that is a result of the offset of the rear rim. Most that purchase the coupe wheels go for them because they will stick out on the sedan. If you want to stiffen the suspension with out lowering it you can replace the shocks or just add sway bars see the sticky on sway bars to figure out which is better for you.