A couple thoughts Samy. 1st I want everyone to remember every time you change the WIDTH of your Rim, the offset number you will need changes. A +15 offset on an eight inch wheel has a different backspacing from a +15 offset on a nine inch wheel. 2nd remember the section widths of same size tires from different manufacturers can vary quite a bit, sometimes more than the 1/2 inch a different width rim will make (i.e. A 265 Falken on an 8.5 inch rim might have a wider section width than a 265 Dunlop on a nine inch rim). 3rd Michelin makes a Pilot Super Sport in a 255/40/18 which is an excellent road course and street tire, I won a couple late model Goodguys auto crosses with Super Sports, and I get them used off Craigslist for cheap...