Elon Musk says Tesla's new Semi trucks are BAMFs. Yes, for those of you at home, that's the widely known acronym for "Bad Ass Mother F***er." Musk playfully threw out the acronym as a "scientific term" Tesla's development team used as they designed the new big rigs. The name sounds ridiculous — but the specs, if they wind up being legit, are actually pretty impressive. Musk claims the Semi can accelerate from 0 to 60 mph in just five seconds, well faster than traditional diesel trucks.