Valvoline Motor Oil porcelain sign features the large lettering with the green and red colors. This sign measures 8 3/4 across and has excellent lettering and porcelain! Whether you are displaying this sign as part of your collection in your man cave, shop, bar, or garage, or giving it as a gift, you can also browse my other auctions for more vintage gas, oil, aviation, automobile, motorcycle, and hunting signs. Vintage Valvoline Motor Oil porcelain sign. 8 3/4 inches in diameter. Bright colors w/ porcelain on both sides.