My friend's '05 Prius doesn't get any better fuel economy than my '02 Honda Accord. Sitting at idle in traffic and stop and go in city what does it.
My choice is diesel.
Years ago I had a cabin in Crown King, AZ and they had a huge truck that was multi-fuel. They told me it would burn almost anything from diesel to vodka.
I understand that genetic manipulation is being used to develop plants that will grow anywhere and when squeezed produce diesel fuel burnable without modifying the engine or fuel system.
Don't some buses in England run on big flywheels that store a tremendous amount of energy. (Although I'd be nervous sitting on a flywheel that, if it gets loose, would go through a 5-foot thick concrete wall!)
Catalytic converters have been developed that just about eliminate any pollution from diesel engines.
Diesel engines are much simpler that gas engines. Why would I buy a hybrid that not only has all the maintenance problems of a gas engine but also maintenance problems associated with the batteries and motors.
With all the furor over global warming I haven't heard anyone point out that the heat from paved land, air conditioners, heating systems, motor vehicles, nuclear power plants, fueled electric plants and many other sources may be causing part of the warming.