That's mostly the difference between large, highly efficient internal combustion engines, and the small, less efficient but extremely portable, performat, and actually-obscenely-sophisticated internal combustion engines in cars.

Electricity is simply efficient-enough of a transmission medium that it does not eat up all of the savings.

How does it make coal or atomic energy more efficient than oil? You get electricity by burning them. When you burn either coal or oil, you loose 70% of energy. Then, you loose delivering the electric power and charging the accumulators. Finally, you have losses in the electric car. You are left with at best 10% of what the coal has supplied. Oil is higly concentrated energy. It could provide you 30% of the energy it contains into kinetic energy of the vehicle.

So, which efficiency are you talking about? Is it the efficiency of warming the planet up? You are on the right track! Burning more carbon fuel is what we crucially need in our age of peak-everything!

Because you only use the explosive power of gasoline when you use it in a car and because you idle much of it away. The savings from transmission and charging do not account for the biggest waste of energy: lack of thermo use in internal combustion engines.

I speak about efficiency per unsubsidised dollar which is generally a rough correlator for usable work per input fuel.

What?

When you use liquid fuel in an engine you are taking advantage of the fact that the fuel converts into a gas quickly and thus increases the relative pressure enough to transfer momentum to the piston head which ultimately powers the drivetrain.

In an electric power plant, this is only part of the equation, the other part is that you also use the excess heat to drive a glycol or water / steam turbine system, recovering much more energy from the fuel.

This makes up for the losses of electricity in the lines. furthermore, nuclear power is by far the safest and most energy efficient source of power. Cheaper, safer, and far more environmentally friendly than a distributed gasoline delivery and combustion system.