[Howard]

Here in Aus our regular unleaded petrol is incorrectly labeled. It should be called "Sh*t that will burn". I should also point out that it will only burn if used within a few weeks of purchase.
My old F15 gets driven maybe 3 times a year, so for that reason I use a fuel stabiliser. It is made by Lucas in the US so should be readily available in North America. It is as dear as poison but has stopped the fuel from going off (and stinking), and stops the carburetor seals from drying out too. I have also noticed that the fuel drain-back is reduced, too. In my previous job I sold it to people who were putting boats into storage over winter, etc. I recommend it.