Vintage Mountain Dew Porcelain Thermometer sign. This vintage Mountain Dew thermometer is a must-have for any collector of hunting and outdoor sports memorabilia. Made of durable porcelain, it features the iconic Mountain lettering at the top and is perfect for displaying in a garage or man cave. Measuring at 4 3/4 by 7 1/2 inches, it is a great size for display. With its bright colors and classic design this sign is sure to catch the eye of anyone who appreciates Soda advertising. Discover More About the Porcelain Signs Available in Our Other Auctions, Which Include a lot of Gasoline brands, Harley Davidson, Smith & Wesson and Other Items. Vintage Mountain Dew porcelain thermometer. 4 3/4 inches by 7 1/2 inches. Vibrant colors and excellent porcelain.