As a programmer my first impression when I read this (if this is actually true) is: "Nice, when we fix those, we'll have done good on car-induced air pollution".
25% of Cars Cause 90% of Automobile Air Pollution
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Re: 25% of Cars Cause 90% of Automobile Air Pollution
#12What does "badly tuned" mean? I feel like there is a need for a lot more clarity. Anyone have the source study (or know what it is). I'd like to know more.
Badly tuned generally refers to incorrect AFR (air-fuel ratios). These can not only cause lower power, but increase the amount of unburned fuel and other chemicals in the exhaust.
On some high performance cars you can even go as far as using the fuel's injection to cool combustion and decrease knock in the combustion cycle of the engine...sometimes this can lead to a richer AFR (more fuel in exhaust gases) which causes pollution.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#13What does "badly tuned" mean? I feel like there is a need for a lot more clarity. Anyone have the source study (or know what it is). I'd like to know more.
Badly tuned generally refers to incorrect AFR (air-fuel ratios). These can not only cause lower power, but increase the amount of unburned fuel and other chemicals in the exhaust. On some high performance cars you can even go as far as using the fuel's injection to cool combustion and decrease knock in the combustion cycle of the engine...sometimes this can lead to a richer AFR (more fuel in exhaust gases) which caus…
These "badly tuned" cars could also have worn out valve seals/piston rings which can cause excess amounts of oil to burn during combustion, adding to the chemicals spewing out the exhaust.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#14What does "badly tuned" mean? I feel like there is a need for a lot more clarity. Anyone have the source study (or know what it is). I'd like to know more.
A summary of the three papers is here: http://media.utoronto.ca/media-releases/traffic-emissions-ma... They just set up some measurement tools by the side of the road and waited for cars to drive by. They didn't check the "tune" of each car or test whether any kind of tune-up would change anything. Edit: more links! Naomi Zimmerman's webpage: http://naomizimmerman.com/publications/ Abstract of the relevant paper: htt…
So that's a pretty significant conclusion to draw without any hard data on the "tuned-ness" of a car.
I wonder how much could be attributed to old cars instead. That's something that would be easily measured by identifying the cars. But that may open a different can of worms if they determine people with the oldest cars are the biggest polluters* because it could be seen as an attack on the poor.
* Odds are the old cars are the biggest polluters.. less efficient to start with, more likely to be out of tune, more worn parts, etc. But I don't have any data to state that as a conclusion.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#15And 16-container ships create as much pollution as all the cars in the world. Perhaps these ships are softer targets to correct than tens of millions of cars?
http://www.dailymail.co.uk/sciencetech/article-1229857/How-1...
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#16What does "badly tuned" mean? I feel like there is a need for a lot more clarity. Anyone have the source study (or know what it is). I'd like to know more.
"badly tuned" for minimal emissions, I assume; tuning for maximum power is somewhat different than for minimum emissions.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#17This is why we should move from mandatory emissions checks on all vehicles, to spot checks of the worst vehicles (but we'd need to get the police excited to run a test.)
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#18Living in a state (Michigan) without any sort of vehicle inspections, I can usually spot a vehicle that will be especially bad well before I smell it. If I'm driving, I'll punch the recirculate button to head off the issue, and look at making lane changes (or even varying my route) to avoid vehicles. This doesn't work as well if I'm walking or biking, however.
I have asthma, so I'm especially sensitive to this. I'd love to see mandatory smog checks introduced here, but I know that this will never be politically feasible. At least our road salt tends to take old vehicles off the road fairly quickly...
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#19Here in Europe (well UK and Spain whee I have lived and owned a car) you need to get a check every year for older cars, and that includes an emissions test. Don't you get that in the States / Canada? (It would appear that the study was done in Canada).
Saying that, go to many less developed country and the cars are far worse condition.
My friend always used to claim that the environmental cost of producing a new car took 9 years to counter with the efficiencies in fuel consumption. No idea how true that is, anyone know?
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#20It's not clear to me weather they included big trucks - the ones hauling stuff. They're diesels which make more particulates and in large quantity. If they are not included, then they should be, because it would be stupid to further regulate cars until we know if they're actually making most of the pollution.