Sorry if this has been discussed on here already. But I wondered which fuel stabilizer/treatment formula you all have had the best results with. For the past couple of years, I've been using the new Briggs & Stratton 5-in-1 fuel treatment. I'd been touting this stuff as the best on the market, since it has no alcohol in it and the manufacturer arguments in its favor seemed to me to be airtight. I didn't base my endorsement on personal experience, which turned out to be a mistake. I swallowed Briggs & Stratton's marketing materials, hook, line & sinker. Yep, I'm a sucker.
I stock new zero turn mowers, and a few of the models haven't moved out so quickly. I used normal 87 octane fuel in them and treated it, when it was fresh, with the Briggs fuel treatment. The bottle says it will keep fuel fresh for 2 or 3 years, depending on how concentrated the mixture is. After draining the fuel from the tanks of the mowers that have been here for a while, I no longer believe this is true. I drained one yesterday that had treated fuel in it for several months, but less than a year. It was orange and had that stale, sweet smell to it. I'm actually surprised that the engine (Kohler 7000 series) ran as well as it did! I replaced it with a gallon of 93 octane, treated with the same stuff. It runs much better now, fortunately. I've recently made the switch to premium pump fuel (93 octane) instead of regular (87 octane), in an attempt to be easier on the fuel systems of the new mower inventory that may be here for several months before it sells. I've even considered using aviation fuel for these units, if it will help me avoid trouble down the road.
What have you found to be the best practice for fueling new inventory without gumming up the fuel system? What fuel treatments/stabilizers work the best, in your experience? Sta-bil, Seafoam, Opti, Startron, Fuel Medic, B3C...you can find anyone who will swear by any one of these, but I don't necessarily trust what they say. What kind of tests have you done?