Wood gas can be used to power cars with ordinary internal combustion engines if a wood gasifier is attached. This was quite popular during World War II in several European countries because the armies active in the war did not always have access to oil.
During and after WWII, supplies of gasoline where low in Japan. To cope with this, a truck, equipped with a "wood gas generator," went into production. Compared to gasoline-powered autos, the lack of power in this truck was impossible to ignore. People often had to get out and push them up hills. Approximately 26,000 of these trucks were produced (based on the Toyota BM model), and at the time were the primary type of available truck.
Gasoline scarcity during the war prompts many BMW owners to mount wood-gas generators on the rear of their cars.