During the first couple of minutes of this clip, you might be asking yourself why a bunch of Tom of Finland types are riding around the desert on motorbikes. Like many of life's great mysteries, all is eventually revealed, if not explained. Speaking of mysteries, differentials are pretty nifty. We still remember getting a fancy-pants Technical Lego set one birthday and spending one week straight just watching the little plastic differential at work. So cool! And speaking of cool, you simply must watch this Chevy PSA about differentials. It's just fantastic. Note to world: many more of us would have gone much further in life if this was the sort of thing we got to watch in school. Full 9+ minute clip after the jump. Thanks to Alex for the tip!