A Dan that is much smarter that me wrote about this very topic. The post talks about fuel economy and the perception that hybrid vehicles are more environmentally friendly.

In Australia, we are lucky that we have Diesel vehicles available at reasonable prices...

1: A Prius.

Great in town. Tolerable on the highway. Bad if you have to steer suddenly to avoid hitting something. New and shiny and nice.

Insofar as there exists such a thing as “an average driver”, a Prius is realistically good for a quite remarkable 50-plus miles per gallon overall if you’re careful, and 45mpg even if you’re not.

You could probably abuse a Prius into delivering only 40mpg if you really tried. Lots of very short trips would do it, if you don’t make judicious use of the EV button. But you wouldn’t have a lot of fun doing that, which rather defeats the purpose of wasting fuel.

2: A Volkswagen Something-Or-Other TDI.

The 1.9 litre Volkswagen turbo diesel, when mounted in its natural habitat (a Golf), is good for a perfectly realistic 55 miles per gallon. Maybe only 45, if you’re a more excitable driver and/or have an older Golf.

You can get at least one and a quarter new diesel Golfs for the price of a new Prius, at least here in Australia.

Like all other diesels, the TDI can run on biodiesel, which gives it more environmentalist bragging points than any petrol Prius will ever have.