Originally Posted by jschmid

Well if you are worried about the roads, loss of ride quality, acceleration, 17s might be a better option. If you want a "larger wheel" look, try to avoid wheels with a lip, that can make some wheels look smaller. As far as how the acceleration is affected...I swap my wheels and tires for winter with some 16" Acura wheels, with 205/50/16, and when I swap back to my 18s in the spring, I notice it for a couple days...just a very slight lag in acceleration, and the last few feet stopping for a stoplight, etc...but it seems like only when the brake pedal pressure is light. It's so slight that I don't notice it after a couple days, and the first couple days it's very subtle.

Just make sure you get some lightweight wheels, no matter the size. My 18x7.5's are 19-20lbs, which isn't bad for what I paid. You can get lighter, but you'll pay more.

Bottom line, if you want 18s...the slight difference in acceleration and braking isn't enough of a factor. In fact if you have real crappy tires right now, the new tires on 18s might actually improve it.