[eeZah7Ux]

That is incorrect. You have to compare the 6kWh where it is used (at the refinery) and the 10kWh available on the vehicle. Both numbers already include the inefficiencies and therefore are comparable.

Which gives to a mere 4Wh of additional power extracted from gasoline.

[fallous]

A "mere 4kWh of additional power" is 67% additional power.

[eeZah7Ux]

Pretty lousy for something that we consider a primary source of energy.