I am literally tripping balls... who spells tire like this?
Pollution from tire wear is worse than exhaust emissions?
171–180 of 336 posts
Re: Pollution from tire wear is worse than exhaust emissions?
#172Hold on: The claim is this: > "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." It does not seem to be a mistake: > "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." A tire might way up to 15 kilograms f…
Most of it must come from the asphalt.
Re: Pollution from tire wear is worse than exhaust emissions?
#173Hold on: The claim is this: > "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." It does not seem to be a mistake: > "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." A tire might way up to 15 kilograms f…
They're torn up from the road and rubbed off from the tyres themselves. The majority is obviously coming from the road.
There's been studies done here in Sweden since we've banned studded winter tyres in some areas of Stockholm in an effort to reduce road wear and improve air quality. I don't know of any sources in English off the top of my head though.
The last time I read an article about it though (2+ years ago, during Diesel-gate), the findings was that the danger in the particles comes from their size with smaller particles being more dangerous for humans. And that road particles were something like an order of magnitude larger than exhaust fume particles from diesel engines.
We've since banned diesel engines inside Stockholm as well so the whole thing is moot here.
Re: Pollution from tire wear is worse than exhaust emissions?
#174I live next to a very busy road (6-lane). When I moved in, the closets were filled with black stains. My brother-in-law cleaned it and said he never saw that kind of dirt. The closets are dirty again.
As time passed I also never encountered that amount of dust. The dust was also extremely different from the dust when I lived in the forest, dark colored and plentiful.
It accumulates very quickly, it gets abandoned-house-dusty in a week.
My breathing also got worse compared to the forest, especially during nights. So there's definitely something dusty around the road.
It was also quite interesting to see that the bathroom gets dusty as quickly too, despite being closed most of the time. It's like the whole ventilation system of the building naturally permeates dust.
Re: Pollution from tire wear is worse than exhaust emissions?
#175Earlier quoted context omitted.
Can someone substantively reply instead of just downvoting this comment?
Look man anyone trying to convince you in 2020 that "plastic is not a significant pollutant" is not arguing in good faith. Please, for the love of god, learn about the climate and the impact of human industry on it.
I honestly believe the anti-plastic movement as well as the recycling movement are at best mass confusion and at worst a way for corporations to divert environmentalists energy away from focus on reducing consumption, reducing travel and reducing human sprawl which would have actual environmental benefits but would hit business growth much more than "buying reusable containers".
This whole, I travel thousands of miles every year but that's ok because I bought a reusable bag shows a complete lack of proportion and perspective. On top of this, the reusable bags take more resources to produce and often they aren't machine washable so they're thrown out anyways once they're soiled, but that doesn't matter because both carrying options have insignificant impact to the environment compared to most forms of consumption.
Re: Pollution from tire wear is worse than exhaust emissions?
#176Maybe offtopic but a surprising bit of extra information regarding wear and vehicles: Road wear scales with the fourth power of axle load, so heavier vehicles do much more damage than one might expect. Take a 40t truck with 5 axles vs. a small car with a weight of 1t and two axles (e.g. VW Polo, maybe an older VW Golf might only weigh 1t as well): (8t axle load / 0.5t axle load) = 16^4, i.e. the truck puts 2^16 (6553…
Do you think that has any bearing on the triple trailer situation that seems to be developing?
Depends how the axle load changes.
Re: Pollution from tire wear is worse than exhaust emissions?
#177Hold on: The claim is this: > "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." It does not seem to be a mistake: > "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." A tire might way up to 15 kilograms f…
"Non-exhaust emissions (NEE) are particles released into the air from brake wear, tyre wear, road surface wear and resuspension of road dust during on-road vehicle usage."
Re: Pollution from tire wear is worse than exhaust emissions?
#178Maybe offtopic but a surprising bit of extra information regarding wear and vehicles: Road wear scales with the fourth power of axle load, so heavier vehicles do much more damage than one might expect. Take a 40t truck with 5 axles vs. a small car with a weight of 1t and two axles (e.g. VW Polo, maybe an older VW Golf might only weigh 1t as well): (8t axle load / 0.5t axle load) = 16^4, i.e. the truck puts 2^16 (6553…
I'd be interested to know how wear scales with tyre pressure. The tyre pressure exactly matches the pressure on one spot on the road surface, so if pressure is higher, a smaller area of the road receives more downward force, causing it to bend and flex, and eventually break up.
> I'd be interested to know how wear scales with tyre pressure.
Apparently not in any way relevance in face of the fourth power rule, as road authorities worldwide just use the 4th power rule for road wear estimates, without accounting for minor factors (type of axles, axle arrangement, surface contact and suspension systems).
Re: Pollution from tire wear is worse than exhaust emissions?
#179Maybe offtopic but a surprising bit of extra information regarding wear and vehicles: Road wear scales with the fourth power of axle load, so heavier vehicles do much more damage than one might expect. Take a 40t truck with 5 axles vs. a small car with a weight of 1t and two axles (e.g. VW Polo, maybe an older VW Golf might only weigh 1t as well): (8t axle load / 0.5t axle load) = 16^4, i.e. the truck puts 2^16 (6553…
> Take a 40t truck with 5 axles vs. a small car with a weight of 1t and two axles ... Truck driver. Not quibbling, just adding nuance. For your typical 40t scenario, allowed max weights are: 12,00 pounds on the front steering axle. It has one tire at each end. 34,000 pounds total on the two tandem "drive" axles on the truck. There are two tires at the end of each axle, so four per axle, eight total at the drive axles…
> Truck driver. Not quibbling, just adding nuance.
You're absolutely quibbling though.
> So you should include in your calculations that the load is spread out over eighteen tires, as above.
The fourth power rule is specifically about axle load, not about wheel load. It's also an estimate / rule of thumb (which is why it's so useful), not a precision instrument.
But hey if you want more precision than the FPR we can do more precision: https://pavementinteractive.org/reference-desk/design/design...
As the link notes, road engineers usually work in LEF/ESAL (ratio to a standardised 18000lbs axle load), and provides some conversion tables.
Assuming a relatively large 4000lbs sedan this is 2000 lbs per axle, or 2x0.0003 LEF = 0.0006 LEF.
A fully loaded truck would be ~0.3 for the 12000lbs front axle, and 1.11 for each of the rear tandem axles, for a total of 2.52 LEF.
2.52 / 0.0006 = 4200. Which shows that the fourth power rule's 4096 was pretty close but if anything underselling it.
Re: Pollution from tire wear is worse than exhaust emissions?
#180They fitted brand new tires and called it a read world test, as if people get new tires every week. Then they measured particulate weight and compared it to ICE emission regulation as if weight was the deciding factor: 5800 ug of rubber particles vs 4.5 ug of PM soot. The rubber could be 1x 5g chunk or 1000x 1ug or whatever. New cars produce mostly small soot, so 4.5 ug can be about 10 000 000 particles¹.
I'm not saying non-exhaust emissions are irrelevant, but I am quite sure exhaust is a much bigger issue, overly so in eastern EU, where people often even remove DP filters and enforcement is lacking.
¹ PM count estimates:
coal density: 929 kg/m³
PM10 particle size: 10 um
PM10 volume: 4/3 * pi * (5um)^3 ~ 4 * (5e-6 m)^3 ~ 5e-16 m³
PM10 mass: 5e-16m³ * 1e3 kg/m³ = 5e-13 kg = 5e-7 ug = 0.5 pg
If exhaust PM was PM10, 4.5 ug would be about 4.5 ug / 5e-7 ug ~ 1e7 = 10M particles, give or take an order of magnitude.