Electricity's efficiency? First, I am an Electrical Engineer so I know more about electricity that you probably ever will.
And:
A heat engine (which every internal combustion engine is!) has a maximum theoretical efficiency defined by the Carnot heat engine model which by thermodynamics is always less than 100% and typically much MUCH lower. And cars and truck are not powered by idealized theoretical heat engine models, they are powered by big ugly gasoline drinking inefficient actual realizations of a heat engine.
Wikipedia has a great page on the internal combustion engine, and in particular relating to it's efficiency (or lack thereof):
http://en.wikipedia.org/wiki/Internal_combustion_engine#Energy_efficiency
Wherein Wikipedia says "Even when aided with turbochargers and stock efficiency aids, most engines retain an average efficiency of about 18%-20%." So that means out of $100 you put in your gas tank, most is already gone and wasted R/T inherent inefficiency so we have about $20 worth to work with to provide real usable work.
Now lets look at the relative weights between vehicle and passenger. I weigh about 180lbs, and my 1994 Dodge Caravan weighs about 3900lbs:
http://answers.bloglines.com/Car/how_much_does_a_dodge_caravan_weigh
So to make calculation easy lets say I weigh 200lbs and my Caravan weights 4000lbs. A close estimate. 4000/200 = 20, or my Caravan weighs 20 times as much as I do! Or it's gonna take 20 times the energy to push my Caravan around as it will take to push ME around!!
1/20 of $20 is ONE DOLLAR!! One dollar out of my $100 spent on gasoline goes to pushing ME around!! That's 1%!! And while I'm a little overweight and my Caravan's not among the heaviest vehicles out there, you should be able to clearly see that no one in any internal combustion powered vehicle is gonna get much better than 1% or so efficiency out of their DOLLARS SPENT ON GASOLINE!!
QED
John Kuthe...
