With more cars on the road and prices for fuel climbing by the day, there is a real need for fuel-efficient transport and ideally low or zero-emission transport at that. Though car makers have made groundbreaking discoveries in fuel efficiency and reducing emissions, there are still even more technologies in the pipeline to help achieve the best of both environmentally friendly worlds. So what are these new fuel-efficient transport options, and are they available now? What's to come in the near future—and beyond?