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Headline > Pollution From Tyre Wear [is] 1,000 Times Worse Than Exhaust Emissions Article > But tyre wear pollution is unregulated and can be 1,000 times wor

Headline > Pollution From Tyre Wear [is] 1,000 Times Worse Than Exhaust Emissions Article > But tyre wear pollution is unregulated and can be 1,000 times worse

ajross 7y ago
Also headline: "pollution", and article "harmful particle matter from tyres". The study was of particulate emissions only, where when we generally think of "car pollution" we're talking about carbon or unburned hydrocarbons or toxins, not smoke. And the comparison was to "what comes out of a car's exhaust", when the overwhelming contributor to the particulate composition of smog is reactions in the atmosphere and not the stuff in the pipe. Not a good headline at all. But still, no doubt tire pollution is reasonable significant and we should all be driving less anyway.
- the8472 7y ago
  "Smoke" is underselling it a bit. Tyre wear creates PM2.5, which is toxic. I don't consider that outright misleading in comparison to misstating an upper bound as a tight bound.
  - ajross 7y ago
    As described in the article, the number they used for the "1000x" comparison wasn't PM2.5 due to car exhaust. It was PM2.5 IN car exhaust, which is quite literally the thing we call "smoke". The vast majority of smog particles due to automobile traffic appear in the atmosphere as reaction products, they aren't in the exhaust.
    - labawi 7y ago
      Are you talking about non-PM (particulate matter) pollution such as NOx, which comes from exhaust but can create ozone?
benkuhn 7y ago
It's true that they weakened the wording in that section of the body, but the description of the actual research does make it sound like the factor of 1,000 was a typical case, not the worst case: > Using a popular family hatchback running on brand new, correctly inflated tyres, we found that the car emitted 5.8 grams per kilometer of particles. > > Compared with regulated exhaust emission limits of 4.5 milligrams per kilometer, the completely unregulated tyre wear emission is higher by a factor of over 1,000. Of course, this assumes that the tyre particles captured by their methodology are (on average) equally bad as exhaust particles, and maybe brand-new tyres wear especially quickly or something. It does seem hard to square the factor of 1000 from this study with the estimate that non-exhaust emissions account for a mere 60% (rather than 99.9%) of PM2.5 emissions. Would be curious to hear from anyone who understands emissions testing better.
- vinw 7y ago
  5.8 grams per kilometer would mean in only 10,000 KM your tyres lose 58 Kg. Seems way off.
  - abainbridge 7y ago
    Yep. Life of car tyre is ~40e3 km. 5.8g * 40e3km = 232 kg. Or 58 kg per tyre. A new tyre weighs about 8kg. I guess it might loose 3kg. So I think they've over estimated by about 20x.
    - justsomedood 7y ago
      Keep in mind too that a tire that has no usable tread life left is still quite heavy compared to the full tread life, new, version because there is so much left for the sidewall and the steel belts inside of the tire. They must be getting this number from measuring something else in addition to the tire
  - rad_gruchalski 7y ago
    I’m really sorry but SI is SI. It’s literally “km” for kilometre and “kg” for kilogram.
cowsandmilk 7y ago
This isn’t an article, it is a press release.
kichik 7y ago
Nothing quite like a grandiose title to make you immediately question each and every word in an article.

Headline > Pollution From Tyre Wear [is] 1,000 Times Worse Than Exhaust Emissions Article > But tyre wear pollution is unregulated and can be 1,000 times worse

ajross 7y ago

Also headline: "pollution", and article "harmful particle matter from tyres". The study was of particulate emissions only, where when we generally think of "car pollution" we're talking about carbon or unburned hydrocarbons or toxins, not smoke. And the comparison was to "what comes out of a car's exhaust", when the overwhelming contributor to the particulate composition of smog is reactions in the atmosphere and not the stuff in the pipe. Not a good headline at all. But still, no doubt tire pollution is reasonable significant and we should all be driving less anyway.

the8472 7y ago
"Smoke" is underselling it a bit. Tyre wear creates PM2.5, which is toxic. I don't consider that outright misleading in comparison to misstating an upper bound as a tight bound.
- ajross 7y ago
  As described in the article, the number they used for the "1000x" comparison wasn't PM2.5 due to car exhaust. It was PM2.5 IN car exhaust, which is quite literally the thing we call "smoke". The vast majority of smog particles due to automobile traffic appear in the atmosphere as reaction products, they aren't in the exhaust.
  - labawi 7y ago
    Are you talking about non-PM (particulate matter) pollution such as NOx, which comes from exhaust but can create ozone?

benkuhn 7y ago

It's true that they weakened the wording in that section of the body, but the description of the actual research does make it sound like the factor of 1,000 was a typical case, not the worst case: > Using a popular family hatchback running on brand new, correctly inflated tyres, we found that the car emitted 5.8 grams per kilometer of particles. > > Compared with regulated exhaust emission limits of 4.5 milligrams per kilometer, the completely unregulated tyre wear emission is higher by a factor of over 1,000. Of course, this assumes that the tyre particles captured by their methodology are (on average) equally bad as exhaust particles, and maybe brand-new tyres wear especially quickly or something. It does seem hard to square the factor of 1000 from this study with the estimate that non-exhaust emissions account for a mere 60% (rather than 99.9%) of PM2.5 emissions. Would be curious to hear from anyone who understands emissions testing better.

vinw 7y ago
5.8 grams per kilometer would mean in only 10,000 KM your tyres lose 58 Kg. Seems way off.
- abainbridge 7y ago
  Yep. Life of car tyre is ~40e3 km. 5.8g * 40e3km = 232 kg. Or 58 kg per tyre. A new tyre weighs about 8kg. I guess it might loose 3kg. So I think they've over estimated by about 20x.
  - justsomedood 7y ago
    Keep in mind too that a tire that has no usable tread life left is still quite heavy compared to the full tread life, new, version because there is so much left for the sidewall and the steel belts inside of the tire. They must be getting this number from measuring something else in addition to the tire
- rad_gruchalski 7y ago
  I’m really sorry but SI is SI. It’s literally “km” for kilometre and “kg” for kilogram.

cowsandmilk 7y ago

This isn’t an article, it is a press release.

kichik 7y ago

Nothing quite like a grandiose title to make you immediately question each and every word in an article.