Motor bus that is driven by wood . Saving of eighty per cent with new fuel . A motor bus driven by gas extracted from wood has been put into public service at Rostock , Germany . The wood is made into gas by a special stove with which the vehicle is equipped . It is estimated that by this means an economy of 70 to 80 percent can be effected in running costs . Photo shows ; The new motor bus with its gas from wood apparatus . 18 December 1933