I had been running P215/40 17 with both stock and lowered Fiestas, but the tire selection in that size is getting pretty bad. I moved to P205/45 17 Michelin Pilot Super Sports and they are by far the best tire I have ever used. Quiet, outstanding traction, great feedback, great wet traction. Of course, they are off the car by the time temps get below 45'F and don't go back on until late spring. I also store them in the house so the rubber doesn't get cold.