[youtube=http://www.youtube.com/watch?v=zYbQDHdgvdY] The EPA gave the Volt a 93MPG rating. I like most people were very interested on how they got that magic number. So they have come up with a video that clears things up for us. The hybrid electric Chevy Volt, which was released in the U.S. last week, presents a particularly unique challenge to rate because GM developed an…