I've never heard that before. Actually, you are
required to use steel lug nuts in PCA and POC race classes (for 911's).
Perhaps if you don't get lug nuts that are properly rounded (convex) to seat into the concave area in the wheel around the stud holes, you'd really trash the wheels!
------------------
Chris C.
73 914 2.0
70 911E Targa
campbell.chris@gte.net