not methanol, methyl hydrate. 2 very different things. my experience with methyl hydrate have been mixed, it does help to raise the octane a point or two but nothing more than that. the stuff burns cooler than gas so it's not good to run with that for very long. a gallon is quite a bit i think, it comes in 1L bottles by me and thats all i would want to put in at once i think, just run your tank pretty empty when you add it.