My dad, a machinist by trade and shadetree mechanic by occasional necessity, used to use 3-in-One in his youth, but being a native San Diegan, has used WD-40 almost since its inception. But not for every lubricating application, of course. White lithium grease has its uses for which WD-40 would be of course completely inappropriate, as does motor oil and assembly lube and gear oil, etc. But we went through a lot of WD-40 over the years.
