"Gasoline stabilizer"

Can anyone point me to an independent study of the effectiveness of “fuel stabilizers” in stored gasoline?

I have started my lawnmower after months without use for decades, without any fuel additives, and never had any problem; used the same gas stored in cans for months. Suddenly, it seems it’s necessary for me to start using a fuel stabilizer, because the gas is supposed to go bad. My experience leads me to believe “if it ain’t broke…”

I’ve found lots of personal recommendations for fuel stabilizers, but no independent studies.

Here’s an article on the subject, http://autos.aol.com/article/does-gas-go-bad/

This problem with gas going bad is more prevelant if the gas contains ethanol.


I guess you now know that BS doesn’t stand for Briggs & Stratton. Some things will run forever without any help, some other things won’t. Maybe. I’m afraid it’s no more definite than that, except when it is. A comedy is when your neighbor can’t start his lawn tractor; a tragedy is when you can’t start yours.

I buy 32 ounces of Sta-Bil every 16 months and “I don’t need no stinkin evidence”. I hope it’s enough for two lawn tractors which I want to keep running. I could care more, but the way I drive those things, I may not see next week.

As someone who engages in small-engine repair, and one who rides/fixes vintage motorcycles, let me assure you gas DOES go bad, leaving varnish/gum in the carb, frequently rendrering it unworkable.

Not necessarily on the scale of “months,” but invariably with “years” of non-use.

To prevent such happening to mowers and/or engines infrequently used,

(1) Drain the tank/run it dry when storing “for the season,” AND undo the carb bowl nut (let the carb pee itself dry).
(2) Undo the carb bowl nut (and pinch off fuel line/close the petcock, as applicable) when anticipating leaving the engine sit for more than 1 mo.

I have various two-cycle engine tools and supposedly you need to start each year with a fresh mixture of gasoline and two-cycle engine oil if you want to start your chain-saw or trimmer or whatever. Each machine works just fine every year with old fuel, although in some case the influx of a fresh fuel mixture improves starting.
I do run my lawn mower out of gas each Fall. I clean the spark plug every year, and drain and replace the oil. If you do these things the mower will start every Spring just fine.

Some two-cycle oil has fuel stabilizer in it. Is it possible you are using one that does?

2-stroke oil, by itself, prevents the formation of hard varnish. As gasoline degrades, (and it does) the small amount of 2-stroke oil keeps the residue soluble so when fresh gas arrives, it will usually dissolve the tar-like deposits kept soft by the oil…

Modern gasoline is made by a process called “Alkalization and Catalyzation”, Cat Cracked for short. This is an unstable product and it WILL revert back to the tar from which it was made.

Some grades of gasoline like Coleman Fuel are straight run distillates and are very stable and can be stored for several years without any problems…