Vintage Hi-Speed Motor Oil Porcelain Sign. This vintage porcelain sign is a must-have for any Route 66 or gas and oil collector. The 12-inch diameter sign features bold black and red colors and showcases the iconic Mother Road American Route 66 Shield in the center. Perfect for display in a man cave, garage, or office, this Route 66 Hi Speed Motor Oil sign is sure to catch the eye of anyone who sees it. This sign will enhance your mancave, collection, shop, or garage. It is your chance to own a piece of Mother Road Motor Oil advertising. Vintage Mother Road porcelain sign. 12 inches in diameter. Vibrant colors and excellent porcelain.