Of Hummers and Hybrids

All the more reason that the standards to be raised a LOT higher and a lot faster than where they are now. The "27.5 mpg" is just a bogus # since they come from unadjusted EPA dyno numbers. The Prius already counts as getting ~65 mpg for CAFE purposes.

Do keep in mind that the 3 CAFE fleets currently are import passenger cars, domestic passenger cars and "light trucks" and the numbers can't be moved around between fleets or between manufacturers. So, creating Priuses (an import car) doesn't mean that Toyota can make the mileage of their Sequoia (a light truck) even worse. However, yes, a more hybrid or non-hybrid light truck can offset lower mileage of other vehicles.

The above is probably why Chrysler classifies the PT Cruiser as a "light truck". The sames goes for the Chevy HHR.

As for Hummers, you want to hear something that will piss you off? The Hummer H1 and H2 are still currently EXEMPT from fuel economy testing and counting against GM's CAFE numbers. It's because their GVWR is >8500 lbs. See Which Vehicles Are Tested. The same goes for monstrosities like the Ford Excursion and Ford Expedition EL.