This is a difficult question as we have no idea what the future holds for us. A simple electrical/gas Hybrid is available at present but in the future, well its hard to say. BMW has a new Series 8 that runs on water, GM has a New design that runs on hydrogen (made from sea water) and gentleman in France has designed an Air powered car with an engine that uses pistons and a Guy in the US has designed an air powered rotary engine. So for the future, you guessed it, we will just have to wait and see.....