Bulky-
Stabil is great for gasoline engines- I wouldn't be without it. Long term storage of diesel presents an entirely different problem- that of water and the microorganisms that grow in it. There are products available to combat this, but if you're running that tractor and bringing the fuel home in 5 gal. containers, you shouldn't have to worry. I'm sure there is more info under "related topics"- Oil, Fuel, and Lubricants. -Stan