Speed Demon Hi-Octane porcelain sign is made of high-quality porcelain and is perfect for collectors looking for a unique addition to their collection. The sign is branded with the Speed Demon logo and has large Hi-Octane Racing Fuel lettering. 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 Speed Demon porcelain sign. Go Fast or Go to Hell! 12 inches in diameter. Bright colors w/ porcelain on both sides.