If you are going from a steel wheel to aluminum, yes, you do. Also, look at the surface of the new wheel and old wheel where the lug nuts hold the wheel, it will either be flat or concave (dipping in). Look at your lug nuts, are they shaped like an acorn at the end? If so, those are to be used with a concave lug wheel. If it is flat, the lug seat of the wheel will need to be flat as well.