I have 18s with a 225/45 tire. i think it looks pretty good. 18s are the way to go

45 is the height, or what you see between the Rim and Fender

225/235/245 is the surface of the tire on the rim.

I actually forgot. lol

lol I'm just assuming you kept stock size :)

I actually don't think I did. I'll have to look into this. lol

well u should probably run 20s if you want a great look. in my opinion, i had 18s with 50 and they filled the wheel well nice but to much tire like a truck tire. im running 245/35/20 and they look nice. i havent been on here in a while so i have to repost my new pics so you can see. though it may still look good with a 40 on 18s. but prob a gap in well?

I personally thing that 245/45/18s look great on the car. thats what I am running right now!

Agreed! And IMO that's when you start the feel the difference in ride quality. It's not too bad, but you start to feel more bumps, and the tires start to get thin enough that you need to worry about rim damage on hard bumps.