I had the chance to drive a 2008 Camry LE over the last couple of weeks and it's an interesting car. A sticker on the rear window claimed that this was a PZEV - Partial Zero Emissions Vehicle. To me that implied it was the Camry Hybrid, which it clearly wasn't. Confused, I did some research. Both the 2.4 4-inline and the 3.5 V6 are now classified as ultra low emission engines (ULEV - Ultra Low Emission Vehicle) because Toyota have fitted the same hydrocarbon-absorbing catalytic converter that's found in the early model Prius. This added constriction in the exhaust system reduces power output from the engine by about 3bhp.
So why the PZEV confusion? Well it turns out there are two classifications of vehicle now. Ultimately, what California wants are ZEVs - zero emission vehicles. Nice idea, but that means hydrogen or electric, which means almost zero vehicles meet that classification right now. As a compromise, the PZEV category was introduced. To classify as a PZEV, a vehicle must:
1. have zero emissions from the fuel system
2. have a warranty that covers 15 years or 150,000 miles
3. meet Super Ultra Low Emission Vehicle (SULEV) tailpipe emission levels
Astonishingly, that last item doesn't just mean hybrids, it now includes a whole glut of cars you wouldn't think were particularly green, including (but not limited to) the Toyota Camry and Camry Hybrid, VW GLI, Subaru Forester, Outback and Legacy, Honda Civic GX, most Mazda 6 models, the Ford Fusion, and in California, the Ford Focus.
Weirder still, if you get out of California where they have a cleaner fuel formulation, the Prius doesn't actually classify as a PZEV any more but as a ULEV instead - an Ultra Low Emissions Vehicle. This gives us the bizarre possibility that by the exact definition used, outside California a 21mpg Toyota Camry is classified as a lower emission vehicle than a 51mpg Toyota Prius.
This does smack of deliberately confusing the consumer so that the car manufacturers can get away with ratings they really don't deserve.