This is not an issue up front, the tire will look a bit stretched though, in back I am not sure, someone else may need to chime in. 285 is perfect for this setup, I think 9.5 may be the maximum rim width for a 255 so you will be stretched pretty far. Best to ask the place you are getting it done. You can check the first page for my pics, the last one is the 285, pretty much perfect flush with the rim and slight protection, a couple up you can see the front 225 is stretched a bit and does not provide much protection. I havnt had either touch a curb yet (park on a street at work daily) but just something to be mindfull of as well, 255 will not give you much buffer in the back. Personally if you can swing it I'd get rubber as well, if you have PS2s or something like that they should be pretty easy to sell here. Again someone more knowledgable may be able to give you a better opinion than I.