I guess I could use them on all my vehicles but since 9 drain plugs are easy to deal with, and oil on my fingers doesn't bother me, I don't bother doing it. Only my 65 F-100 uses one since the oil drains on top of the cross member than drains backwards down over the brake line and the rear ledge before hitting the oil pan. A big mess to clean up so there is a valve in use here where I attach a clear hose to the valve before opening and drain the oil directly to the pan. Now about that horizontal FL-1A also over the cross member.