There is always some gasoline left in the mower, lawn tractor, snowblower, and other gas powered yard equipment at the end of the season. Draining the tanks for storage is messy, and often results in unhealthy spills. But, with the addition of Sta-Bil, there is no need to drain gas tanks.
I’ve been using Sta-Bil for years, and it always works, even when I don’t follow all the directions exactly. It’s simply a liquid that contains a proprietary mixture of petroleum distillates and additives (in other words, they aren’t telling exactly what), which keeps gasoline from breaking down during storage. Without adding this to equipment tanks, it’s unlikely that the machine will easily start months later, when you need that piece of equipment again.
It comes in a 4 oz can with a lift up squirt spout. This amount will treat a 5-gallon tank. Since most of my machines have a smaller tank, I have to try to estimate how much to add. That’s not difficult, but it is a little tricky to decide how much of the can you have added. Since it’s a steel can, you have to judge how much you’ve used by shaking the can lightly. They do tell you that seven full squeezes is about 1 ounce. On the web site, it shows a translucent plastic container, so perhaps they have changed from steel cans since I bought any. The new container also seems to have a screw top spout. That would be great.
After you add the Sta-Bil to the tank you are supposed to run the engine for 5 minutes to work it through the system. There have been a lot of seasons that I haven’t done this. For example, usually by the time I remember to add it to the lawn tractor (sigh- I usually get it in after the snow starts), the tractor will no longer start without having the battery charged. But if I get the additive in the tank, it always seems to start in the spring.
It has an oily, solvent kind of smell. If you get it on your hands, you’ll need to wash well. You aren’t supposed to get it on painted surfaces.
The directions say that the product prevents the formation of gum and varnish in tanks or gas cans for up to 12 months. It can be safely used in 2-cycle or 4-cycle engines. You can use it with Ethanol-blended fuels, and is actually recommended to help prevent corrosion from ethanol, but I don’t have any personal experience on this point. It does come in larger containers for people with more engines to protect.
They also make a product specifically for marine use, and another for diesel engines.
It is made by the Gold Eagle company of Chicago, Illinois.