PiusesPriuses get low- to mid-40s in real-world driving in California, on California gas, which because of various processes results 10-15% less milage than in surrounding states. (My car went from 27 mpg freeway to 23 when I went from Arizona gas to California gas.)

Prius mileage is indeed roughly equivalent to non-hybrid cars, but those cars are either light-weight strippers without modern safety equipment (multiple airbags, body reinforcement, etc.), or they're diesels, which emit sulphur and carbon soot. So you can't really argue that they're not fuel-efficient relative to other gasoline-powered cars comparably equipped.

For example, I had a 1994 Civic hatchback that got from 37 - 45 MPG, but it had no air conditioning, no power steering, no sound deadening, and it was a manual transmission. Whereas a Prius comes with A/C, power everything, a pretty slick navigation system, four doors, and a pretty large cargo bay. If you haven't been in one, they're surprisingly roomy -- about the equivalent of a mid-sized car, NOT a compact.

/not a hybrid fan
//is a car nut