25% of Cars Cause 90% of Automobile Air Pollution
1–10 of 157 posts
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#2Title should be: "25 Percent of Cars Cause 90 Percent of Vehicle Air Pollution"
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#3Title should be: "25 Percent of Cars Cause 90 Percent of Vehicle Air Pollution"
[deleted]
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#4What 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.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#5What 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.
[deleted]
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#6What 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.
In our old car, the catalytic converter wasn't effective, and the cost of fixing it was more than the car than the car was worth. The check engine light was on constantly as a result, but it was easy to ignore. Judging by the smell of that car's exhaust, it was definitely in the 25%.
Bad air-fuel ratios also cause lots of pollution due to unburned fuel being sent out the tailpipe. I would think that this is less common with fuel-injected vehicles, but there are still plenty of old carburated vehicles on the road, especially where road salt isn't used.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#7What 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: http://atmos-meas-tech-discuss.net/8/2881/2015/amtd-8-2881-2...
This PDF is labelled "supplemental" but it looks like the full text of the paper. http://atmos-meas-tech-discuss.net/8/2881/2015/amtd-8-2881-2...
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#8Title should be: "25 Percent of Cars Cause 90 Percent of Vehicle Air Pollution"
That's more likely to mislead, because it implies a difference between 'Car' and 'Vehicle', and 'Vehicle' can include trains, ships, planes, etc.
25 percent of Automobiles Cause 90 Percent of [Automobile] Air Pollution.
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#9What 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.
The common term for such vehicles is "gross polluter". Here's a study on them (pdf warning)
Re: 25% of Cars Cause 90% of Automobile Air Pollution
#10What 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.
It seems there's more to it than just badly tuned - it seems how to drive also effected the results:
"The most surprising thing we found was how broad the range of emissions was," says Evans. "As we looked at the exhaust coming out of individual vehicles, we saw so many variations. How you drive, hard acceleration, age of the vehicle, how the car is maintained – these are things we can influence that can all have an effect on pollution."
Not sure how they can tell "how a car is maintained" or "how you drive" from spot checking 100K with a roadside probe... anyone have thoughts?