Evone,

The main issue is the battery and sufficient 'average' power to go up (or down) a mountain (or just a long hill) at high speed (requiring a large ICE-Generator or fuel cell). A series hybrid is mechanically simpler than a parallel hybrid, but it requires not only a higher capacity battery; the battery must be able to handle high currents without overheating. The battery in present parallel hybrids is treated gingerly to allow them to last 'the life of the car'. There are no available batteries (yet) that can hold up under the strain of being the primary source of energy for a family car at a reasonable price.

Your comment on the 'innefficient' regenerative braking of parallel hybrids is somewhat incorrect as the losses are mostly due to battery charge-discharge losses and some in the generator-motor losses which is identical to those in a series hybrid (or pure EV).

Remember, we have to be able to afford to buy and maintain the vehicle (the Tesla, a two seater, costs how much?). My 2004 Prius cost me $23,000 and has required only minimal maintenance in 67,000 miles.

Please go easy on conspiracy theorys. Big Auto (US) is just run by stupid executives with no vision. Big oil has little to say about what cars get produced and sold; all they can do to prevent efficient vehicles (and alternate fuels) is to keep gasoline prices low and that doesn't seem to be something they can do any longer. DARPA has unlimited funds (our tax money) so don't assume that their solutions suit our needs.

JeffD