We may come off like know-it-alls around here, but I'll let you in on a little secret: We don't know everything. What don't we know?

We've asked you this before, and it resulted in us learning some really great lessons. Well, the time has come for us to find out what else we really don't know. What's an automotive, aerospace, or other mechanical fact that we just really don't know?

Drop them in the comments!