Okay, I am going to try some stuff in my fuel. However, I will need to add under 1/2 oz per fill up. I can measure that small amount easily. The question is, how do I get it into the fuel tank? 1/4 to 1/2 an ounce doesn't seem like enough to use a funnel; it would just get the funnel's surface wet and none would get into the tank. But if I don't use something to get down past the inner fuel filler door, I'm afraid the charcoal canister will simply soak up all the additive. I don't know whether that will damage the charcoal can or not, nor whether it will release the additive later. What do you think?