I have a 94 honda accord 4 door with H&R 1 and a half inch drop. right now im running 215/30/R18, and theres a gap. by installing 225/40/R18 will this make my car rub or ride rough?  

im not sure how wide are the tires 7 1/2, 8?  

You have to consider if the 40 series tire will hit the bottom of the upper control arm. How much space is in there for this new aspect ratio increase? And how much closer is the upper outer edge of the tire going to be from the fender and upper rear wheel well. I'm assuming that by going bigger that you've taken into consideration that your speedo will read slower than you'll actually be going? Do a little more research before you make the change. You could always use a little space there, unless you're going for the slammed look! And josh18 is right... how wide a wheel assembly are we looking at? There isn't much room there to begin with!