I always heard that the old duffers with their two wheel drive tractors working in gravel pits and such would mount one rear tire backwards so that they could get extra traction backing up. I am not sure how true that is, my Grandfather later told me it was just the line a person used when they mounted the tire on the rim in the wrong direction! "Oh that, welllllllllllllllll, yeah I meant to do that. Aides in backing up when doing loader work."
Nice excuse though! Kind of along the lines of,"My dog ate my home work."