Reply #54: That figure completely ignores 40 miles of pure-electric drive time.

[TheWraith]

"Why should generating electricity, and using it at once, be much more efficient than using the mechanical power directly?"

Because it is. Simple as that. An electric motor does more work for less input energy than it would take to do the same work mechanically, because it's much more efficient. And because it can use stored electricity, generated at stations which produce much less CO2 per unit of energy than

Look at it this way: a gallon of gas contains 33 kilowatt-hours of energy per gallon. Let's assume you have a typical compact car that gets 33 miles to the gallon. That means that it takes 1000 watt-hours of gas to drive that car one mile.

In comparison, the Tesla Roadster--an ultra-high-performance electric sportscar--requires only about 250 watt-hours of electricity to drive the same distance.