With all the talk about ethanol fuel and bad gas, which fuel stabilizer is the best to use? They all seem to claim to reduce the effects of ethanol and prolong fuel life... but is there a clear winner in the bunch?  I've seen StaBil, Star Tron, Sea Foam, STP, Briggs & Stratton Fresh Start.

Stabil is reliable for gas stabilization. SeaFoam is what we used at the marina prior to putting boats up for winter.

Sta-bil has one now for marine use that counteracts the ethanol fuel.
 
I've used regular Sta-bil for 8 years with no carb related issues on all my equipment. Have not tried other brands.

We used Sta-bil red religiously for years. I had two fuel problems in 10 years. Three trucks in and out of seasonal storage. Ten- 4 cycle mowers and equipment, 20 or so hand held equipment each year in out of storage. We now use Sea-foam. The cost is more but no problems in five years. But that is just to stabilize the fuel in storage and to clean carb. We do not use any gas with Ethanol in any of our equipment. If you are looking to solve the problems that Ethanol creates in gas with phase separation I'm told to use K100. Two of the newer trucks we run we do use regular pump gas 10% Ethanol. I will be putting in some K100 starting this year.

I use seafoam, and sta bil blue (marine?) In every fill up/can. The newer fule not only is prone to phase sep but the shelf life is extreemly short. If you are unlucky enough to be stuck with ethanol like me in New England do yourself a favor and start using a higher octane fuel. Leave the low grade 87 at the pump. Use high grade or mid grade at least. This way if you do get a little water in the fuel tou will still have useable gas once you strip the water out.

I can be more technical if anyone wants but this is a simple example.

Gas with ethanol suspends the water rather than letting it fall to the bottom like conventional fuel. Reformulated gas holds the water like a rain cloud, once the gas cant support the weight of the water it falls out stripping the ethanol from the gas. No ethanol means no octane and low octane translates to no burn.

So by using a higher octaine fuel you have a better chance of salvaging your gas should you get phase separation.

There is more science to it like temperature, % of ethanol etc. But...

Jesse

Sta-Bil Red for fuel stabilization. Seafoam to clean out the fuel system. After years of using Sta-Bil I've had no carb issues. Doesn't cost much either. Cheap insurance against a gummed up carb at the beginning of snow season.

I've had really good luck with the Briggs stabilizer. Part #100118 for the 8 oz size. I use this in all my personal equipment and I sell a lot of it in my small engine shop. Every can of fuel I get for the shop or myself I add the Briggs stabilizer, both 2 and 4 stroke.

I have used everything on the market over the years.  One word => Seafoam!

Briggs no longer supplies Fresh Start, it was not compatible with E15 fuel. They now have Advanced Formula which seems to work very well. We did get complaints of a gray residue left in the fuel system, it is actually a corrosion inhibitor.

I have never used any fuel stabilizers on the riding mowers I have had. So far 22 years and only 1 carb cleaning.
I use Stihl 2 strokes, use motomix when rarely using, stihl ultra(oil) with high test gas when using alot.
I have used Seafoam on my atv a few times years ago but stopped using it. Seafoam used to be around $4 where I live, now it's $8 - $12.