Also have you ever looked into gasifiers?

I would like to make one some day. They are vehicles that are modified to run on wood -- pellets, branches, twigs, a chair, an old 2x4, doesn't matter -- rather than gasoline.

Check em out. 

My deeper thoughts on this topic -- bc my initial thoughts are to stock gas -- 

There will be foreign intervention in any American "SHTF". Gas will still arrive. In the statistically most-likely of the bug-in\bug-out scenarios, gas might not be needed, and\or the military would be locking down civilian traffic. Maybe commandeering fuel supplies.

If the whole world is hit by an extinction-inducing asteroid, having transportation won't be helpful necessarily. 

If you were far enough from the point of impact and any subsequent seismic\volcanic activity, you'd have very limited amount of time to get to somewhere else, and unless you also were ready with hydroponics and a chicken coop or at least massive food stores, you'd starve if you stayed put and used that fuel to wait for "when the dust clears".

So personally, I think wood is a more valuable fuel than gas. Lasts forever. But others who are not prepared will have every tree uprooted in any area with other humans in it, so you shouldn't wait for the day after to gather wood. It takes decades to grow a big tree but just days for all the wood to be chopped.