I would stick with a brand name, no telling what is in the no name aftermarket stuff. I have had good sucess with Sea Foam, Stabil, Lucas, and I am sure there are others that folks have had good sucess with. These additives are designed to treat fresh fuel to keep it from going stale, none will work well treating fuel that is already old !! Also mix according to instructions, just adding a little to a large tank of fuel wont work very well.