While ethanol and methanol are the default fuels in T2k, they actually aren't the best fuels available.
Wood Gas, mentioned over at RPG.net, is a widely used alternate fuel.
There's plenty of wood, and it's easily harvested. Here's a schematic of the system;
The other fuel, especially suitable for military vehicles, is
biodiesel. Often this uses ethanol as part of the process, but you can get a fuel almost as good as petroleum diesel without the hassle of invading Rumania.