Mothballs aren't entirely made of one single ingredient, so you have no real idea what you are putting in the tank and its likely you can get dissolving lumps caught in your fuel filter and fuel lines when you put them in. Also there is no ethanol in mothballs. There is no methanol either. Mothballs used to contain napthalene which is what was believed to boost the octane levels, but its unlikely you'll find it in the majority of mothblls these days they use a different ingredient called Dichlorobenzene which is a pesticide also used in urinal cakes. Regardless, napthalene has been shown not to improve performance, emissions or fuel economy, just ask a company called BioPerformance that sold napthalene pills and were then forced by the industry regulator to repay customers over $8 million after the napthalene pills were actually tested. The mothballs that contain dichlorobenzene could possible have an effect on octane because of the benzene. But dicholorobenzene is just one ingredient in those mothballs, and even then it is (simply put) two parts chlorine to one part benzene and chlorine will, at the least, wreck your o2 sensor. So either way, its not a smart idea. Just buy some octane boost!
