One more thing regarding the previous post ... California poiticos who want to allow hybrids in carpool lanes are quick to say that not all hybrids will get in.
For example, hybrids must get at least 45 mpg. Sounds straightforward, but is it?
Consider the Civic hybrid. The EPA says it gets 48 mpg (combined city/highway). But when Consumer Reports tested it in real-world driving conditions it got only 36 mpg. So would the Civic hybrid be granted special access to carpool lanes or not?
Of course, 36 mpg is still really good mileage, but it's only about seven mpg better than the regular Civic.
And what about air quality benefits? There are plenty of non-hybrids that are extremely clean. Should they get in?
And think about cutting pollution like cutting fat. Say a dieter decides to cut the fat by going from low fat milk to skim milk, yet he maintains his habit of eating a dozen donuts a day. Not exactly the best possible plan.
Now think of non-hybrid new cars as low fat milk and hybrids are skim milk. Regular new cars are actually very clean (about 98 percent cleaner than cars built in the 1960s), but they're not quite as clean as hybrids.
Then there are the old clunkers. These are the gross polluters (the donuts). This is where most of the pollution is.
So if you want to cut fat, target donuts; if you want to cut pollution, target old clunkers.