Yes you are correct cars do run just fine on ethanol fuel, but your car very rarely if ever sits for weeks or maybe a month at time and it is not 2 stroke. Ethanol fuel it self is not the problem, Phase separation and water absorbsion are the culprits in 2 stroke engines that require oil in the fuel to oil your cylinders. Phase separated fuel will smell and look totally different than any Gas you have ever been around. Stations fuel can separate in the tanks even very busy stations, the only way to salvage separated fuel is to add multiple gallons of isopropal alcohol to the tank and aggitate till it absorbs the water were it can be burned thus increasing the acohol percentage. If you want to know why I know this is because i worked for a company that built and repaired fuel station equipment and we got regular calls to fix separated fuel and a station will spend some money to not loose 3000 gallons of fuel. For you old timers remember HEET, if you ever looked at the ingreidients Alcohol It fixes water in fuel. Ethanol bad for 2 strokes and anything that sits for extended periods of time and anything carburated.