Acura3.0CL

Hey, i knowticed my front left tire has a few slash marks in it...every couple of inches theres a slash and its too perfect and round to have been done be someone...im thinkin its either a defect in the tire or when i crank the wheel all the way, somethin might be rubbin and causin it to slash the side-wall...but i have 225/40/18's and everyone says to get 225's so i thought i woudnt have any rubbing problems...whats the deal..has this happend to anyone elce?? what should i do? what should i look for??