If all the people in the US would drive electric cars, you obviously need electricity to do so. Let's assume the power stations use oil the generate electricity. How much oil would you need to keep all these electric cars in the US going? Would that be more or less oil the US consumes now for keeping its cars running?
Except we are in the US, which is blessed with 27% of the world's coal reserves (by far the largest; Russia is second with 17%).[1] So there is no reason we would burn oil to generate power.
Even better would be generating all that electricity with Nuclear power, since the "middle east" of Uranium is Canada and Australia, with 28% and 22% of global production, respectively.
Of course there are better options than to use oil to generate electricity. But what I am interested in is: what is more energy efficient? x million combustion engines or a few centralized power station plus x million electric cars?
Let's assume we would all drive a Tesla: http://www.teslamotors.com. Who will do the math?