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Dust from car brakes more harmful than exhaust, study finds

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Re: Dust from car brakes more harmful than exhaust, study finds

#131

Post by _benedict »

chongli wrote: post #58
bfgeek wrote: post #26

Earlier quoted context omitted.

To add to this, (from what I remember reading the study at the time) it was basically racing a car around a track (think lots of tyre squealing around corners), and found that the tyre wear was very high. I haven't seen a study which actually simulates somewhat "normal" driving (presumably because the wear is so low driving like that it's difficult to measure). Also didn't factor in a bunch of different stuff - tyres…

A normal driving test was (famously [1]) done to measure the effect of axle load (vehicle weight per axle) on road wear. This is where we got the “fourth power law” of road wear. I think as a starting point, I would expect that tire wear should remain roughly in proportion to road wear, given the same tires on each vehicle. From this, I would expect car makers to use larger, thicker, heavier tires on heavier vehicles…

This assumes that road wear and tyre wear are caused by the same mechanism, but tyre wear is presumably caused predominantly by friction, whereas road wear is at least in part (and perhaps predominantly) caused by compression, creating pot holes by causing the earth underneath to move.

Re: Dust from car brakes more harmful than exhaust, study finds

#132

Post by [deleted] »

porphyra wrote: post #120
ndsipa_pomu wrote: post #7

I think this is missing out on the big issue - tyre pollution which contains really nasty chemicals that inevitably get washed into rivers and waterways. Also, car-shaped EVs often use regenerative braking which will reduce the amount of brake dust pollution, but with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles. https://earth.org/tyre-pollution/

The Tesla Model 3 Long Range weighs 1823 kg. The BMW M340i xDrive weighs about 1818 kg. Seeing as these two cars are similar in size, capacity, and performance (0-60 mph in 4.2 s), it is nice to see that the electric option weighs about the same as an ICE car of similar specs.

[deleted]

Re: Dust from car brakes more harmful than exhaust, study finds

#133

Post by rnikander »

fortran77 wrote: post #77
01HNNWZ0MV43FF wrote: post #32

Earlier quoted context omitted.

For the weekend trips you could put in an engine with a power splitter Oh what's this, turns out the ideal car was already invented twenty years ago, it's the Toyota Prius Casually gets 50 mpg city and highway Small, lightweight battery Not a super expensive status symbol The plugin models use very little gas for the daily commute, but you can always drive it like a pure ice car if you need to flee the country on zer…

The Volt was a much better idea. It could be an all electric car—at any speed—for 50 miles or so.

Agree, the Volt seemed like a good idea. I don’t know the inside story of GM discontinuing that car. I imagined it was corporate dysfunction.

Re: Dust from car brakes more harmful than exhaust, study finds

#134

Post by AnthonyMouse »

ndsipa_pomu wrote: post #119
AnthonyMouse wrote: post #110

Earlier quoted context omitted.

> However, if we get as many people to use e-bikes or e-scooters, then the size and weight issues pretty much disappear. I still don't understand how they expect to solve the occupant safety issue though. Cars travel at high speeds but have crumple zones and airbags. E-bikes travel at the same speeds but if you crash, you die. And 2-wheeled vehicles are easier to crash. The fatality rate for motorcycles is astonishin…

Some measures can be taken such as reducing urban speed limits to something like 20mph and increasing traffic enforcement so that riders/drivers have an incentive to take sufficient care. There's also the possibility of creating separated infrastructure to allow the smaller/lighter vehicle riders (e.g. two/three wheelers) to not have to tangle with car and lorry drivers. However that requires political will and infra…

Speed limits are set for the conditions, e.g. they're lower in an area with high pedestrian traffic than on the highway. But that's just dodging the issue; what do you do about the highway? Traveling at higher speeds on the appropriate roads is good and people want to continue to do that. You want plumbers and firefighters to be able to travel quickly from one side of the city to the other. So then you've got a highway, but if you put two-wheeled vehicles on it then people die, and if you disallow two-wheeled vehicles on it then people buy cars instead.

Ironically, the somewhat obvious solution to this would be smaller/lighter cars (e.g. one- or two-seaters), but they can't pass the safety standards required for cars even though they would still be dramatically safer than two-wheeled vehicles.

Re: Dust from car brakes more harmful than exhaust, study finds

#135

Post by ndsipa_pomu »

bfgeek wrote: post #26
foobazgt wrote: post #17

Earlier quoted context omitted.

This is fake news. The backing study for this claim did all sorts of wonky unrealistic testing to come to this conclusion. If you own an EV, you viscerally know it's BS given that you're the one paying for the actual tire replacements on your real-world driven vehicle.

To add to this, (from what I remember reading the study at the time) it was basically racing a car around a track (think lots of tyre squealing around corners), and found that the tyre wear was very high. I haven't seen a study which actually simulates somewhat "normal" driving (presumably because the wear is so low driving like that it's difficult to measure). Also didn't factor in a bunch of different stuff - tyres…

I'm surprised there isn't more info available to compare vehicles/tyre wear. There's plenty of real-world driving going on, so you'd think someone would have measured tyre replacement frequencies.

Re: Dust from car brakes more harmful than exhaust, study finds

#136

Post by dijit »

lazide wrote: post #115
dijit wrote: post #106

Earlier quoted context omitted.

I find it hard to take the debate seriously because the default stance of everyone against electric 2-wheelers is not manual bikes, its cars. And, cars are multiple orders of magnitude more dangerous than anything on 2-wheels. I’m sure you’re right that theres room for improvement, but instead of building infrastructure (we literally shaped cities for cars after all)- we would rather ensure that cars are incumbent fo…

Cars are far less dangerous for occupants than 2 wheeled vehicles.

Perhaps there is less incentive then to drive dangerously.

Re: Dust from car brakes more harmful than exhaust, study finds

#137

Post by rbanffy »

n8henrie wrote: post #128
porphyra wrote: post #120

Earlier quoted context omitted.

The Tesla Model 3 Long Range weighs 1823 kg. The BMW M340i xDrive weighs about 1818 kg. Seeing as these two cars are similar in size, capacity, and performance (0-60 mph in 4.2 s), it is nice to see that the electric option weighs about the same as an ICE car of similar specs.

The "0-60 mph in 4.2 s" is doing a lot of the heavy lifting in this comparison.

The BMW is a lot nicer than the Model 3.

Re: Dust from car brakes more harmful than exhaust, study finds

#138

Post by ndsipa_pomu »

_benedict wrote: post #131
chongli wrote: post #58

Earlier quoted context omitted.

A normal driving test was (famously [1]) done to measure the effect of axle load (vehicle weight per axle) on road wear. This is where we got the “fourth power law” of road wear. I think as a starting point, I would expect that tire wear should remain roughly in proportion to road wear, given the same tires on each vehicle. From this, I would expect car makers to use larger, thicker, heavier tires on heavier vehicles…

This assumes that road wear and tyre wear are caused by the same mechanism, but tyre wear is presumably caused predominantly by friction, whereas road wear is at least in part (and perhaps predominantly) caused by compression, creating pot holes by causing the earth underneath to move.

It's quite noticeable (to me at least) that the areas with highest wear are usually places that have heavy vehicles (buses and lorries) braking and accelerating. Traffic lights and bus stops will often have bumps/dips that seem to demonstrate a shearing force between the road surface layers.

Re: Dust from car brakes more harmful than exhaust, study finds

#139

Post by blackoil »

isx726552 wrote: post #78
ndsipa_pomu wrote: post #7

I think this is missing out on the big issue - tyre pollution which contains really nasty chemicals that inevitably get washed into rivers and waterways. Also, car-shaped EVs often use regenerative braking which will reduce the amount of brake dust pollution, but with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles. https://earth.org/tyre-pollution/

This is why a move to natural latex rubber tires is necessary. Companies have experimented with them[1][2] but a world-wide switchover should be in the works. [1] https://www.continental-tires.com/about/sustainability/activ... [2] https://arstechnica.com/cars/2023/04/eco-friendly-tires-brid...

"natural latex rubber"

Worldwide switch-over will destroy forest ecosystems in Malaysia, Indonesia and Africa and more to replace it with Rubber tree plantations.

Re: Dust from car brakes more harmful than exhaust, study finds

#140

Post by ndsipa_pomu »

santoshalper wrote: post #112
ndsipa_pomu wrote: post #7

I think this is missing out on the big issue - tyre pollution which contains really nasty chemicals that inevitably get washed into rivers and waterways. Also, car-shaped EVs often use regenerative braking which will reduce the amount of brake dust pollution, but with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles. https://earth.org/tyre-pollution/

Yeah, but you know it's not going to the get the coverage it deserves, since it's not a problem in the US, where we use tires instead.

It doesn't matter how you colour the issue
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