After having the fuel lines turn to goo on 2 Stihl chain saws, 1 Troybuilt weedeater and a lawn mower I started using Startron in all the gas I keep in gas cans and have had no more of these issues for several years. A mechanic recommended it to me and it has worked so I stick with it.
I can't say what it would do for a tractor. Are you having problems? If not I wouldn't use anything.