Can human urine be used as a replacement for gasoline?

…I can take a small sip of water before going to bed and by 2 AM it has turned into a quart. So, I’m thinking that if I drink a gallon, by morning I can fill ‘er up for free.

NOTE: An elaborate best answer awards ceremony requiring formal wear will be conducted May 23, 2008 at 9 AM on the Walmart parking lot at the intersection of U.S. Hwys. 77 and 287 in Waxahachie, Texas. You need not be present to win, but if you are there please bring a 5 gal. can of gasoline as a contribution in case this urine thing doesn’t work out.