Energy News: It's in black-and-white at Toyota.com --the 2007 Prius Hybrid averages 55 miles per gallon . Or does it? Not according to the new real(er)-world calculations  from the U.S. Environmental Protection Agency. The Prius' actual MPG is more like 46 -- still pretty darn good. But the point is, ratings everywhere are going down being with the 2008 model years. Even the Hummer loses some of its precious fuel economy. Explains the Wired article: "Overall, vehicle city mileage estimates dropped by about 12 percent, and some vehicles are expected to be rated 30 percent lower, according to EPA documents. The new EPA tests factor in real-world conditions such as speeding, varying weather and lead-footed driving. Vehicles like hybrids with smaller engines pay a higher penalty during the acceleration test, as well as the tests that simulate going up a hill and maintaining highway speeds."