[WardL]

You can't really buy E100 legally since it is controlled by the Bureau of Alcohol, Tobacco, Firearms. When ethanol is blended into gasoline it is already denatured with 2% gasoline before being blended. E85 is pretty available around the country and at 110 octane is probably more octane than your Cobra is set up to take advantage of. Your carbureted Cobra will run fine on it, but over time you might have some melting rubber issues. I expect all fuel line material you can buy today is good for E10, but maybe not E85. Gasoline or ethanol has nothing to do with damaging the ozone layer. That was Chlorine in CFCs. As it turns out, modern engines with computer controlled fuel injection do not require ethanol to burn clean. Your Cobra will still fail every emission test even if burning E100. It is the engine design with a catalyst, fuel composition and computer controls that make low emission. Ethanol is not required anymore.