I changed from the 255/55 x 18 to a Firestone Destination LE2 245/60 x 18 which is slightly taller and slightly narrower. It looks nice. It does have a more compliant ride and no problems, but I miss the firmness in the turns of the old size. I kinda regret it. I'm not even a very aggressive driver.
There is a neat website. Just Google "rimsntires" and at the page use the "Size Comparer" tool. It won't answer your question. But it's neat.