As you have been answered well; once you have a good working gasifer/engine combo AND THE EXPERIENCE PROPERLY OPERATING THESE you would not need any gasoline at all.
Gasoline can be readily stored for at least 3 years. Out to even 5-10 years. Not cheaply though. Non-ethanol marine grade "clear" gasoline with Briggs and Stratton brand preservative at 1 ounce per gallon in air tight plastic cans good for 3 years.
The 5-10 years needs the same more expensive "clear" gasoline; NATO spec metal cans; and a preservative called PRI??. Can't fully recall the name.
Wasn't a time frame I felt sustainable. Gasoline would get personal "emergency" used up. Bartered away. Or stronger arm, stolen.
Propane "gas" is the longest term storeable. As such an excellent fuel though, none be able to streach even a 500-1000 gallon tank past 3-5 years of winter heating/ summer AC cooling.
Electric saws nice . . . but. Contact brushes DO wear out in a few hundred hours.. Get spares ahead. Practice replacing. Chains do get filed down worn. Practice minimal removal hand filing. Electrics starting torque snaps off chain teeth. Experience shows the need to upgrade chain size. This means a wider kerf cuts; more power used up. ALL batteries use/age, and need replacing out. Expensive to spare ahead on these.
Experienced? Oh Yes.
Realistically a five year at best solution without new outside materials inputs.
Hand processing is always the back up, reliable.
DO/Practice before the need. Bought the crosscut files? Bought the tooth setters?
I can hand process enough wood fuel chunks in 45 minute a day to replace the small engine equivalent of one gallon of gasoline.
Use/Practice before need. Learn to base-needs electrical energy live daily on the energy equivalent of one, no more than two gallons of gasoline daily is the only safe bet.
No gasifner/engine needed to do this. Just a little gasoline genny. You will find your self pre-invnesting in many LED lights; small wattage electrical plug-in's. Upgrade change out old high energy refrigerators, freezers, cloths washing machines. DO THIS NOW. With out slaving out your children woodchunk fuel making you cannot DIY gasifiy out of grid-made-possible, energy-pits.
Make damn sure any gasifer system you buy into for SHTF can run on hand processable wood chunks. All pellets will be used up quick. Pellet making, wood chip making are very energy input needful. SHTF and these will no longer be made. Just not personal DYI possible. Need lots of BigHydro/Nuke/Fossil fuel "energy slaves" to make these.
Good question set you put up.
Just-In-Case Steve Unruh
Fuel wood p