Fuel Stabilizers and Winter Storage

When the leaves start to turn colors some of us begin to think of fall and having to put our antique vehicles in storage for the winter months. One thing we need to think about is the gasoline in the fuel tank and what happens to it over the winter. Modern gasoline typically has about a 90-day shelf life starting at the refinery. The gasoline you buy at your local station is most likely 30 days old when you buy it.

The point here is the gasoline in your fuel tank will turn sour before the birds and the flowers greet you in the spring. You need to add a fuel stabilizer to the fuel in your tank to prevent fuel problems in the spring.

Most of us have experienced gasoline that has turned sour. It plugs up fuel filters, gums up mechanical fuel pumps, plugs up main jets and idle circuits in carburetors…and the list goes on.

I started researching fuel storage additives about ten years ago. When modern gasoline began adding alcohol to the mix it changed how I prepared the cars entered in what is now the Hemming’s Great Race. The alcohol in modern gasoline especially affects cars put in storage for the winter. Modern alcohol gasoline can absorb up to 13 oz. of water in a twenty-gallon tank.

What I also discovered was that not all fuel stabilizer additives are created equal and that nearly 40 percent of the fuel additives sold contained alcohol as their primary ingredient! Good Grief! That is what we are trying to get rid of, why would you add more alcohol to your fuel tank!

If you have read my gas and oil book you learned how to read a MSDS sheet to figure out what is in a fuel stabilizer additive.

Meanwhile…after I figured out what should and should not be in a fuel stabilizer additive I looked to see if there was anyone worse off than we were.

Here is a short video from Briggs and Stratton on the affects of alcohol gasoline.

I discovered the small engine people (landscapers especially) were having a terrible time, much worse than we were… which makes sense considering how easy it would be to plug up a jet in a small engine carburetor for example.

So I called and talked to the engineers at Briggs and Stratton and Stihl numerous times and almost wore out my welcome both places, but I found out what I wanted to know. I called most all of the other companies for input but either got no response or no return phone calls, and one who said, “That’s not our problem …” and hung up!

Then I worked on shell life of the additives. Some additives are good for three months and some as long as three years. That is quite a difference. If you have more than one collector vehicle or lawnmower, weed eater, chainsaw, snow blower, who wants to have to treat them more than once during the winter?

So in the end here is what we use for the Great Race cars and is what I use in my own vehicles.  It is made by Briggs and Stratton, one ounce treats five gallons (it is concentrated obviously, no use buying filler) and one 8 oz bottle treats 40 gallons. And the best part, one treatment is good for up to three years, by far the longest of anything else on the market, AND…it contains no alcohol. It is available under the "FUEL" heading in the "PARTS" drop down link, or by calling 785-632-3450. I hope this knowledge helps keep your antique vehicle on the road and saves you a little heartache and aggregation in the process. 

Update - We used to sell the Briggs formula in 16 oz bottles. As of November 2019 the Briggs and Stratton fuel stabilizer is no longer sold in 16 oz bottles. It has been replaced by 8 oz bottles. Same formula same 3 years of protection and same 1oz treats five gallons so if you are slow at math, an 8 oz bottle will treat 40 gallons.

The change was due in part to Prop 65 in California which also resulted in the price increase. I do not many any extra money on the price increase and have no choice but to pass it on to you. No matter the cost increase it is still worth every penny as you will discover once you use it.