I honestly think the best propulsion technology for surface vehicles for the time being is clean diesel. Clean diesel does not have the heavy smoke, smell, or noise normally associated with diesel cars. It does everything well- vehicle range, cost, torque, weight, infrastructure, etc. although there is a slightly higher cost per unit to make a diesel engine than a gasoline engine. It is not as wide a margin than electric or hybrid. Diesel fuel itself can eventually be swapped without vehicle modification to use biodiesel. Talk about freedom from oil dependency, that is the best solution. It as to be done not to impinge on food production but we already have the technology needed to to manufacture biodiesel in large quantity, all we need is a political incentive to pay for the heavy up-front investment needed to set up the processing facilities. Not so with electric- it is not a technologically mature science due to the low energy-to-weight capacities of lithium-ion batteries. While it is a good long range plan, it is too far from economically feasible now to attract drivers who want a vehicle that is highly similar to what they already have in gasoline. I noticed the purchase price of a leaf is $32k and for that much money I can have a much nicer vehicle in a gasoline car.