I didn't read all the replies to see if this was mentioned, but a lot of octane boosters have hydrocarbons that are larger than normal fuel. So they can prematurely clog your fuel filter. Something to keep in mind.
I just ordered a 6 pack of boostane professional, if i read everything right its about 5 ounces to 5 gallons of 93 to make 100 octane. Bottles will last longer than torco.
At the season's end just be sure to run a full tank of regular pump gas thru the tank before using the Stabil or other winterizer for off season storage.