PRI-G Gasoline Treatment Today's modern gasoline has neither the storage stability or energy value it did just a few years ago. PRI-G is a refinery-grade treatment specifically designed to make today's gasoline burn more completely for maximum performance, efficiency and reliability. Since PRI-G prevents gasoline from forming fuel system and engine deposits and has also proven to restore old gasoline to like-new condition. One ounce will treat 16 gallons of fuel.