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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

#161

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.

My first generation bmw i3 is exactly this. Later models got much bigger battery packs.

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

#162
post #103

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.

Maybe, but the average Tesla tire lasts half as long as my tires typically do, and the extra weight from the battery combined with the high onset torque are likely culprits (the former of which you can't fix with current battery technology when comparing otherwise apples-to-apples ICEs vs EVs if the EVs have non-negligible range, and the latter of which would require artificial limiting on the electric motor (which c…

The weight difference between a Model 3 and the average new car sold in the US is a negative number. The Model 3 is slightly lighter than the average new car. So the difference comes entirely from torque.

But you could just... not have such a heavy foot.

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

#163

How many kilograms of brake dust does the average IC car produce in a year, versus gasoline burned? March of Dimes Syndrome here. We're entering the end of the gasoline car era. Anti-car activists need something else in order to continue kvetching, so it's down to tire and brake dusts, battery recycling and whatnot. When that is solved, it will be about the harms of exterior paint, and inhaling the "new car smell". T…

> Transportation that is not powered by one's own muscles can never be virtuous.

... unless said transportation puts users in close physical proximity to strangers, some of whom are loud or dangerous. Such transportation is very virtuous: the more numerous, dangerous, or annoying the strangers, the more virtuous the transportation. This exception is not applicable to transportation that flies or floats.

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

#164

Earlier quoted context omitted.

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 highw…

Furthermore, when I've eaten at the sidewalk area of a restaurant near a theater I go to in the summer, the protected bike lane has truly terrifying combinations of traffic outside of cars including what I guess are electric motorcycles. And, because it's a "bike" lane, a ton of users basically just blow through the red lights.

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

#165

> with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles. This has been shown not to be true in a number of studies.

Every study I've seen concurs that EVs chew through tires faster than their equivalent ICE vehicle, and generate more tire particulate matter accordingly. The reasons (torque and weight) are unambiguously greater in an equivalent EV vs ICE. EVs do generate lower brake particulate matter, by virtue of not using them as much (otherwise they'd also be prone to generating more in a (faulty) per-engagement direct comparis…

Studies are always good, but it almost trivially follows that the tread loss must go somewhere.

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

#166

Earlier quoted context omitted.

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 highw…

Plumbers and firefighters have stuff to haul and long distances to cover. They need to do 40/50/60mph on the freeway, and 15/20mph on local surface access roads where they're mixed in with light vehicles.

The whole light-vehicle thing is predicated on low speeds and relatively short distances (up to about 15 miles). Most urban areas, even fairly sprawling ones, that's enough to cover a pretty substantial % of trips.

It's about using 1/10th the weight and 1/50th the power to cover a big % of the same tasks. Personally I'd say the bike/scooter/golf-buggy, and then either an owned or shared car for the last 10% of trips where you need to use the freeway is a better optimum than high-speed light vehicles, because as soon as you get to about 25-30mph you need impact protection, and the design constraints quickly escalate to "absolutely no smaller than a Fiat 500".

There's also ofc the option of mass transit for some of the longer distance stuff, at least in cities that are able to build it.

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

#167

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.

That’s more a consequence of the absurd micro-hybrid setups modern ICE use to cheat emission measures. The 2015 340i weighed 300kg less

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

#168

> with their increased weight and powerful torque, they produce a lot more tyre pollution than ICE vehicles. This has been shown not to be true in a number of studies.

Can you share them? Because physics says that damage to roads scales quadratically with weight. Not sure why tires would not experience a similar increase. At the very least, these tires are subject to higher forces due to the heavier weights of EVs. Intuitively, consistently applying higher friction forces to an object would cause higher wear.

The weights aren’t really that much higher than ICE cars, but I don’t think anyone who has owned an EV would say they don’t go through tires faster. They do. How much due to weight, how much due to better acceleration, I don’t know, but they definitely are harder on tires.

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

#169
post #88

The Yale article and the paper both highlight the fact that EVs use regenerative braking and produce less dust. I was worried that this was a rehash of the astroturf campaign from a few years ago focusing on EV weight and how that was so bad for the environment because of tire and road wear. Unfortunately you need to read through the whole thing (instead of the headline and a few paragraphs) to see that information.

Has someone actually measured that tradeoff (weight versus regenerative braking) to determine where it is an even tradeoff? And surely regenerative braking has its own shedding of particles from all the moving parts.

[deleted]

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

#170
post #88

The Yale article and the paper both highlight the fact that EVs use regenerative braking and produce less dust. I was worried that this was a rehash of the astroturf campaign from a few years ago focusing on EV weight and how that was so bad for the environment because of tire and road wear. Unfortunately you need to read through the whole thing (instead of the headline and a few paragraphs) to see that information.

Has someone actually measured that tradeoff (weight versus regenerative braking) to determine where it is an even tradeoff? And surely regenerative braking has its own shedding of particles from all the moving parts.

There are EV's which have drum-brakes. That's only possible because the regenerative braking takes most of the load. Also, there are stories of brake-discs rusting out on EV's. Both point to less (friction)-brake use on an EV compared to an ICE.
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