I possibly might pick up 225 45 17 size tires for my car. My current tire size is 225 50 or 55 17 can't remember right now. Would the ride be harsher if I went down in height? I believe that's what the middle number stands for. Correct me if i'm wrong. These are just temp tires till I get some rims later. Has anyone put the g35 19" coupe rims (made by rays) on a g37 sedan before? Just curious how they would look.

 

your OEM tires are 225/55/17. If you went with a 45 series tire, your overall diameter will reduce, which will effect your speedometer. Your sidewall will also decrease, which will effect the ride. Coupe 19s are very common on sedans.

Not my car, but here are G35 coupe Rays on a sedan

 

^what he said. Keep in mind when shopping for rims that tires for 20" rims are quite a bit cheaper than 19"s, just something to consider. Both 19s & 20s with the 35/40 sidewalls will roughen up your ride but will hold the corners much better (assuming you're on quality treads).

 

Cool thanks for the replies. This will help with my decisions.