If you want my opinion on the ethanol blend fuels read the post below. If you have not choice, and want to make your car more robust to the negative effects of the ethanol (exaggerated by most of our cars being periodic drivers), you can upgrade the fuel tank and lines to stainless steel, replace your fuel pump, rubber fuel hoses to a modern rubber compound material and then re-jet the carb accordingly. At that point the car will be more robust to the fuel as it sits in the system, but it will not prevent the damage due to phase separation which is a real concern. This is what can lead to a low octane mixture or even pure water being sent to the engine.

Also, be aware that not every state has laws stating that the gas station has to even tell you if there is ethanol in the pump. Some states will have to tell if its there, and others how much is in it.


https://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=259207&page=1