In 1967 a Turbine powered car nearly won the Indy 500. To prevent future turbine dominance the air intake was limited so that this type of power process could not compete effectively against the reciprocating power plant.

In the future it is possible we will see a resurgence of turbine automotive technology as "power averaged" hybrid processes allow for operating the turbine at a near constant output throughout the transportation cycle. This could be accomplished through series hybrid technology where the turbine charges a temporary storage device at a constant rate and the variable demand is pulled from the storage device.

Regenerative braking will assist in reducing the average demand from the prime mover.

Heat Engines are simply not very efficient. I doubt your new automobile has an efficiency of even 30 percent. The upside to this is that this low efficiency is what makes regenerative braking so attractive. Why? Because in a system where the efficiency is only 33 percent it takes 3 units of combustion energy to do 1 energy unit of work. In a 33 percent efficient process, if 1 unit of work energy can be regenerated then it saves 3 units of combustion energy.

End use efficiency is the best way to approach increased efficiency when the prime mover is a heat engine. Coal fired, grid distributed electrical energy is a great example of this. Here the efficiencies are less than 15 percent at the plug. Save one unit of work energy by higher end use efficiency or conservation and it reduces combustion demand by 6.6 combustion energy units.

Understanding this very basic truth puts a different light on a broad range of energy related issues.