[Chemist_Geek]

who can afford exotic cars

For what one spends on a top-flight Ford Excursion, one could buy two Prii. Even an Escape is equivalent pricewise to the Prius. The fully loaded Focus is also priced close, but only gets a pathetic 34 MPG on the highway.

[John Jamieson]

Another way to look at it:

In round numbers:
Toyota Prius burns $3,000 worth of gas and $4,000 worth of batteries per 100,000 miles. Similar Toyota Echo burns $4,000 worth of gas, and $100 worth of batteries per 100,000 miles. Which is Greener?