Sierra Ethanol fuel and treatment stabilizer. Sierra eGuard is a multifunction fuel additive that is specifically formulated to solve the problems caused by ethanol-blended fuels from E5 to E85. eGuard prevents the gum deposits that can clog carburetors and injectors. It will also remove any existing gum or carbon buildup by breaking these deposits apart so that they can be burned off with the fuel. eGuard significantly enhances the combustibility of fuel so that it burns more completely. Treats up to 40 gallons of fuel. 8 oz. Sierra Part #18-9775.