I normally don’t fall for additives because most are probably nothing more than snake oil. That said, I want to share my experience with a product called Archoil.
Years ago I met a guy in a gold prospecting meeting that was selling a fuel product called Archoil AR6200. I was skeptical to say the least but I bought a small bottle and started using it anyway. I made a 2000 mile round trip towing my trailer that was identical to a trip I took the year before and my average MPG on the test trip increased by about 1.5 mpg or 10%. Later I started using their AR9100 friction reducer for the crank case.
This last weekend I went to start my 3HP B&S tiller motor after it had been sitting for over 3 years with fuel in the tank. I was amazed when it started with just a few pulls on the start cord and it ran fine until I killed it about 5 minutes later. I did not add fuel but I did spray starting fluid in the carb because I really didn’t think it would start. I expected a new or rebuilt carb at least.
I wanted to share this because I wasn’t sure about it's use as a fuel stabilizer until now. I am a true believer and use their products in the RV, generators, boat, motorcycles, autos, yard and garden equipment and spare cans of gas. It’s pricey but takes just a few ounces per tank of oil fill.
I buy from an online speed shop to safe on the price.
Following is a link to the company where they have more information including data sheets and another link to a video posted by Jay Leno and his mechanic.