I have the oem rims 235/60R18 for my 2004 XC90 and I was going to mount 255/55R18 instead but someone mentioned the tires will slightly rub on full turn and when loaded. I do think the 255/55R18 make the car look nicer and at the same time I have more options.Right at the end of my ownership I put 255/55-18 Pirelli Scorpion Ice & Snows on. They fit fine on the stock wheels. If you run the calcs on the height they are only 1/2" taller than the stock size. Much easier to find tires in this size also. For the short time I ran them they were immensly better than the Michelins. Quieter on the Highway and great on ice/snowpak. I've got them in the garage now waiting for next winter and some 18" wheels for the Toy.