 Two such commercially made vehicles are the Sinclair C5 and TWIKE.According to a recent comparative energy and environmental analysis of the vehicle fuel end use (petroleum and natural gas derivatives & hydrogen; biofuels like ethanol or biodiesel, and their mixtures; as well as electricity intended to be used in plug-in electric vehicles), the renewable and non-renewable unit energy costs and CO2 emission cost are suitable indicators for assessing the renewable energy consumption intensity and the environmental impact, and for quantifying the thermodynamic performance of the transportation sector.This analysis allows ranking the energy conversion processes along the vehicle fuels production routes and their end-use, so that the best options for the transportation sector can be determined and better energy policies may be issued.