This topic came up over Thanksgiving, so I was curious what the energy efficiency of vehicle is. These numbers are all very rough, but they should still be interesting. Also these are energy efficiency, so the more hp you are using the more energy you are using.

Car (.81)(.25 engine)(.70 transmission*) = 14%

More efficient car (.81)(.27 engine)(.84 transmission*) = 18%

*I donâ€™t believe the 50% number based on the 15% rule for dynos.

Hybrid car (.81)(.39 engine)(.84 transmission*) = 27%

F1 car (.81 **)(.47 engine)(.89 transmission) = 34%

** I know an F1 car does not run on pump gas.

Coal Power Plant to Electric Car:

Electric Car (.31)(.89 charging and battery)(.9 motor)(.9 drivetrain) = 22%

Electric Car new power plant (.96 coal extraction)(.98 coal transportation)(.9 boiler)(.47 turbine***)(.95 generator)(.95 transmission of electricity)(.89 charging and battery)(.9 motor)(.9 drivetrain) = 26%

The wiki says modern power plants with reheat cycles can reach 47% I donâ€™t know if that is the turbine or the whole plant.

[Edit some additional calculations based off of discussions below:

Hybrid car (.81)(.40 engine)(.84 drivetrain*)(1.05 regeneration****) = 29%

****This number is made up for reference, and may very wildly with driving habits, route, traffic, and terrain.

New Automotive Diesel (.81)(.46 engine)(.84 drivetrian) = 31%

F1 car (.81 **)(.49 engine)(.91 drivetrain) = 36%

Electric Car mixed power supply (.96 fuel extraction)(.98 fuel transportation)(.53 power generation)(.95 transmission of electricity)(.89 charging and battery)(.9 motor)(.9 drivetrain) =34%

Electric Car new power plant (.96 fuel extraction)(.98 fuel transportation)(.6 power generation)(.95 transmission of electricity)(.89 charging and battery)(.9 motor)(.9 drivetrain) =39%

Also, I have no clue how efficient an F1 drivetrain is and the KERS is assumed by included in the total engine number.

End of Edit]

Some efficient vehicles for your time.