When you're a bouncer at a New York City nightclub, it apparently behooves you to use a fake name. So that's what buff actor Vin Diesel did, trimming his last name Vincent to get his new first name. The Diesel, he once said on Late Night with Conan O'Brien, came from friends who said he was always full of energy. But something about his huge biceps says it might have something to do with muscles.