Would a Toyota Prius make a good high mileage car?

the 3 major exhaust pollutants are Carbon Monoxide (CO), Oxides of Nitrogen (NOx) and non-Methane unburnt hydrocarbons (UBHC or just HC)). In the pre-control era, it was common for any given brand-new car, right off the showroom floor, to produce exhaust having a CO content of 4 to 6 percent or more, a UBHC concentration of over 700 ppm, and NOx emissions of over 7 g/mile. (No, I didn`t make up the units of measurement. Yes, I know they`re all different and the grams-per-mile one is dumb.)
Compare that to a new `98 car, or a new `99 car, or a new `02 or `03 car. A regular one, not a hybrid. Its CO, UBHC and NOx readings will all be zero or a gnat`s crotch hair`s width away from zero. 0.0045% CO, 0.006ppm UBHC and 0.01 g/mi NOx would be typical readings. That is almost zero, especially compared to what went before. Now suppose you chop those emissions by fifty percent. In real-world terms, there is absolutely no effect upon the cleanliness of the air if the car emits 0.00225% CO instead of 0.0045, 0.003ppm UBHC instead of 0.006, and 0.005 g/mi NOx instead of 0.01. Back when we were chopping CO emissions in half and going from 4 percent to 2 percent, that was one hell of a big achievement and had enormous, dramatically positive impact on air quality. But as is the case with any kind of cleanup effort, the closer you get to "absolutely clean", the less significant becomes each incremental change.
There are two other factors at work of which you seem unaware, as well. Firstly, the statement that a vehicle is "90 percent cleaner than a ULEV vehicle" is misleading. It compares a vehicle to a standard, not to another vehicle. The xLEV standards (LEV, ULEV, SULEV, etc.) specify maximum emissions levels above which the vehicle does not qualify for each classification. It does NOT mean that every vehicle in that classification emits the maximum allowable levels for that classification, just as it does NOT mean that every vehicle not in that classification exceeds those levels. If you are an ad copywriter, and you see that the Toothgnasher Superflash you`re advertising emits 0.05 blogs per mile, 0.1 percent Frogtoadium Oxides and 0.25 ppm Doorknobium Nitrate, and you see that the RLEV standard permits a maximum of 0.1 blogs/mile, 0.2 % Frogtoadium Oxides and 0.5 ppm Doorknobium Nitrate, then you can write "The Toothgnasher Superflash is 50 percent cleaner than RLEV!" with an almost-clear conscience. The part you`re leaving out by doing so, of course, is the fact that the 0.1 blogs/mi, 0.2 % FOx and 0.5 ppm Dk Nitrate are the *maximum* allowable emissions for an RLEV, and that in fact actual RLEV vehicles produce emissions similar or identical to those of the Toothgnasher Superflash.
The other factor is the fuel upon which the vehicle is operated. Vehicles are certification-tested (which is where all those numbers and xLEV certifications come from) on fuel of extremely precise composition and extremely high quality. Real-world pump fuel is of wildly inconsistent and depressingly poor quality. A recent extensive study showed that Ontario`s relatively filthy fuel, high in MMT and Sulphur, for instance, rapidly deteriorates the emission control performance of new cars, *and that the deterioration was greater with more advanced emission control systems*. They`re absolutely right, and Ontario`s fuel (which I`m picking on, but it`s only just one of many areas where the fuel, not the vehicles, are the limiting factor in cleaning up exhaust emissions) needs serious help. But the implication is that a vehicle with a less-advanced emission control system can have real-world emissions lower than a vehicle with a more-advanced emission control system.

emissions is often used. The term is often used to signify a vehicle that produces no exhaust gases what so ever, no CO2, no water as it moves along. Of course these vehicles are not zero emissions either, their emissions come from some coal plant making electricity somewhere else. I think a proper term would be displaced emissions vehicles.

What Dan has stated so eloquently can be summed up a bit less eloquently:
"Advertising claims such as `90% cleaner than ULEV` are equivalent to saying `ten percent of nothing is still nothing.`"

it back up on a solar cell, then you could say zero! ;-D

emmisions in 1975. The fact is that ULEV cars still emmit pollution and are not zero and almost zero is relative and makes no sense, you can suck on my tail pipe and see if its almost zero. Maybe its so low that we never need to worry about them polluting. I don`t know. I found a website that says in 1975 the average car emmited 1.5% CO content, thats 33 times more than the ULEV, but there are also significantly more cars on the road and increasing, is this good enough to not go any further? I don`t think we can make that assumption.

the fact that you`re specifically not debating it suggests you need to go back and have another good, hard try at reading the information that has been presented before trying to respond to it.

you put it on the web if it isn`t true. Admit it a website is a perfectly adequate substitute for actual working knowledge of any topic.

Finally, in pre catalyst equipped cars of the 60`s and early 70`s, the typical CO output at the tailpipe was 3.0-5.0% and HC was 300 -700 ppm. I used to repair cars back then and recall well all those retrofit NOX and PCV systems that had to be installed in cars not so equipped at the time of resale in CA.
The job is done.

difference, but the point I was making was that ULEV standards are not essentially zero, just a lot lower and still contribute to air pollution. If you breath my exhaust from my Echo I`m sure it will kill, maybe take longer than an older car, but will still kill you.

Would you care to go back for a third try at reading what was written? You might want to try sounding-out the hard words.

oil is burned somewhere else, and there are significant losses in transport, storage, and conversion before it makes it to the road in an EV1.
From some estimates I`ve seen, there are less pollutants released by driving a SULEV internal combustion engine than an electric car because the cars are cleaner than the electric plants.

Toyota`s hybrid technology manages to produce only 19% of the unburned hydrocarbons produced by a similar car without hybrid tech? It also cuts NOX emmissions down to 8% of the equivilent car, and only 51% of the CO. (to see the comparison, try comparing a 2002 TOYOTA ECHO (35.6 mpg, LEV) and a 2002 TOYOTA PRIUS (48.6 mpg, SULEV) at < http://www.environmentaldefense.org/tool.cfm? tool=tailpipe > not what this thread was about. It was about hybrids. I won`t go into the fact that GM had much more demand for it`s EV1 than it could supply, and tha the Toyota and Honda hybrids have only recently been able to keep up with demand. CO2 CO NOX HC 1978 TOYOTA COROLLA 7349 lb 629.7 lb 66.1 lb 55.4 lb 2002 TOYOTA ECHO 6812 lb 154.3 lb 9.4 lb 4.1 lb 2002 TOYOTA PRIUS 4990 lb 79.9 lb 0.8 lb 0.8 lb (hybrid)
If you use PPM, it sounds good, but you can see the tons of polution in the air when you drive through LA. What you can barely see are the surrounding hills. The emissions can be counted in pounds per year, and for large vehicles some pollutants can be measured in tons per year per vehicle.
Sit on interstate 405 any summer day, with your eyes burning and and unable to read the dingy grey freeway signs, unable to see details on the hill a mile away and tell me the job is done.

Philip, it works, but its not cabon monoxide poison that gets you, its starvation, will take about 2-3 weeks. But usually the wife will open the door before then, and you have to start all over again, so they usually just give up and iron out their troubles. :-D

instead of having dialogue I`ll just let it go.

re-read and re-read what everyone else on group managed to "get" the first time through; you`re obviously not equipped to "have dialogue" on the matter. That`s not assholishness on my part; it`s just reality. More than anything, it`s a sad reflection on the critical-thinking skills not taught in our schools.

2.3L engine); it isn`t necessarily hybrid that brings the emissions from LEV to SULEV levels. There are also non-SULEV hybrids, such as the Honda Civic hybrid, and most versions of the Honda Insight (note that Honda has a SULEV version of the non-hybrid Accord).

your argument (which is actually a regurgitation of material found on the website of "Environmental Defense", an advocacy group)
1) You are comparing a car to a standard, which is misleading and invalid. Cars must be compared to cars, and standards to standards.
2) You are missing or eliding the point that "only 51% of the CO" (for instance) is meaningless when the baseline number of which you are only producing 51% is itself essentially zero. were very heavily subsidised, the demand just wasn`t there and the maintenance on the vehicles was problematic and expensive. in the Hydrogen economy of 2103. The geography of the "Valley of Smokes", as the native name for the area translates, creates the problem.