Hagerty has a video on their website with two Shell engineers. They said that the new formulation of the Shell Nitro+ gasoline premium was especially formulated with older carburetor engines in mind. They said that the fuel has a special formula that would coat the older plastic and rubber parts and protect them from the dangers of ethanol in modern fuels. Also no lead additive was needed for the older cars. Has anyone had any experience with this fuel in muscle cars, carburetor cars etc.?